CROSSING THE BORDER: CULTURAL IDENTITY AND HISTORICAL INTEGRATION OF NATIONAL MUSIC AND POPULAR MUSIC

Music is a form of artistic expression and an important carrier of cultural and historical development, containing rich cultural content. This paper summarizes the characteristics and differences between typical musical instruments by analyzing the origin and historical development of national music and popular music. It analyzes the distribution of music-cultural circle, at the same time, to analyze the interaction between national music and popular music more comprehensively, this paper discusses the promotion and promotion between national music and popular music from the perspective of cultural identity and historical integration. Cross the border of national music and popular music, further enrich the forms and ways of mutual reference between the two, and strengthen the integration and development of the two, which can enrich the cultural connotation of popular music and make the expression form and content of national music more diversified, laying a foundation for the spread and development of national music and popular music in modern society.


INTRODUCTION
As one of the essential carriers of spiritual life and value pursuit, music is not only a part of cultural soft power but also carries the pursuit of the human spirit and value performance. Therefore, its influence is also rising, and its role as a link between cultural exchanges and historical inheritance is more pronounced. Popular music is more widely accepted in the current music field because of its popular content and light rhythm. It is famous for different ages. The transmission range and speed are optimistic enough (Brown, 2008;Roy & Kumar, 2012). In addition, with the help of commercialization and capitalization of popular music development, its spread is more rapid and extensive. Compared with the excellent trend of the development of popular music, due to the influence of geographical conditions, customs, language differences, and other factors, the audience range and popular area of national music are relatively small, leading to more significant restrictions on the excellent inheritance and development of national music culture (Wang, Y, 2022;Shi, J., & Ning, Q, 2022). Popular music and its cultural influence significantly impact the national music culture, but the phenomenon is only in the form of influence. The core aesthetic quality still embodies the different forms of national culture and historical development. Through the mutual reference and integration of culture and history, popular music and national music achieve their own artistic value and charm in their fields. To jointly create a new music culture, combining national music and popular music has shown to be an inevitable trend (Gunara, Setiawan & Cipta, 2022).
At present, with the strengthening of globalization and the acceleration of the modernization process, in the process of the development of national music and popular music, based on the cultural and historical development background of national music and popular music, the selection of music that is more in line with modern social aesthetics and recognition has become an essential part of modern music research, The elements of popular music and national music are infiltrated and integrated into a more dynamic music creation form. In the creation process of popular music, the excellent integration of national music elements can make the two constantly integrate and innovate and continue to promote the high-quality development of music. In music development and update, new elements are constantly absorbed. In contrast, the dross of traditional music is abandoned, and the updated iteration of music development is gradually formed, promoting the continuous development and progress of national music and popular music. Figure 1 shows the general law of music development (Xu, Y., 2019;Jun, X. 2019). The continuous development of music, from the beginning of music's origin, gradually develops into traditional music with time. In the process of integrating traditional music with new music elements, traditional music constantly absorbs nutrients from new elements and, at the same time, discards its dregs and then develops into a new music type; On this basis, it circulates. With the progress and development of social culture and history, music is gradually iterating to update a new form more suitable for appreciating the aesthetic and constantly enriching and enriching its connotation. For a long time, from the perspective of external forms of expression, national music and popular music have been significantly restricted in the level of cultural identity and historical integration, leading to an inevitable controversy in the music field on the prospect of further integration and development of national music and popular music (Ming, Z., 2019). However, with the expanding needs of national music and popular music for their living space and cultural and historical development background, national music and popular music inevitably merge and gradually establish a close relationship of mutual dependence. On the one hand, the integration of new elements, such as the way of popular music playing and the way of voice making, makes national music revitalize, more resonate with the audience and also gives it traces of the times, laying a solid mass foundation for the breakthrough of the national music form; On the other hand, national music gives popular music a profound cultural connotation. Popular music is better survival and development depend on the profound cultural soil of national music. It profoundly integrates and internalizes the elements of national music and finally realizes the embodiment of national characteristics of popular music itself (Shahid, M, A, K. & Mohammad, S,. 2017).
Cultural identity confirms the cultural belonging relationship between culture and the identity of individuals and national groups. From the cultural and historical development perspective, "identity and integration" is a concept of great aesthetic significance in music. It is an inclusive absorption of different music cultures and a sense of identity for self-music culture (Yuli, C., 2019;Gao, W., 2020;Xinyu, B., 2022). Therefore, coordinating and integrating popular and national music continue to emit a unique appeal. The emergence of classical music and excellent composers is inseparable from the recognition and integration between the two. Tchaikovsky's creation is often regarded as "the more national it is, the more global it is." while absorbing Russian music elements, it also integrates Western Europe's mainstream composition thinking and techniques. This perfect recognition and integration enable his works to transcend the times and borders and become classics, which continue to be popular worldwide. In addition, the triumphant rise of national music based on the "Chinese style" also provides more reference for the integration and development of national music and popular music. More and more music creation is committed to integrating national and popular music, laying a foundation for the cultural identity and historical integration of national and popular music.

DEVELOPMENT OF NATIONAL MUSIC AND POPULAR MUSIC
National music is a form of national strength and a further improvement and refinement of cultural identity and historical development accumulation, which has an essential role in emotional expression and mutual communication (O'Grady, Abidin, Lee, Kaye, & Bondy, 2023;Jezi ń ski, 2022). Modern popular music originated from the West, characterized by marketization, popularization, and homogenization. The emergence and development of popular music is also affected by the development of traditional national music culture. Therefore, the development of popular music is based on the gradual development and evolution of the influence of traditional national music culture and also shows traces of the influence of national music. The analysis and understanding of national vocal music and modern popular music can clarify the influence of national vocal music on modern popular music culture to promote the more profound development of national music and popular music cultural identity and integration (Roy, W., 2022). In addition, in the integration and development of national music and popular music, the impact of music on mood changes can be more comprehensively understood through the psychological emotion model, as shown in Figure 2. The pleasure arousal model is given based on the research and classification of psychological emotions. Literature, art and science, and technology in modern society have made significant progress and development. National music is also developing with modern literature, art, and technology. However, the historical culture of national music still shows all its unique tenacious vitality. For national music, this tenacious vitality shows its unique cultural value after a long period of historical precipitation (Nichols, 2022). The musical instrument is an essential primary carrier of music development and a tool for music performance and communication. For the history of the development of national music in the world, Horn Postel's and Sax's instrument four division method is one of the internationally accepted methods. This method is a classification based on the excitation mode of the instrument object sound source. Based on the "Horn Postel-Sax" four-division method, in the order of the history of the emergence of musical instrument archaeology, it can be divided into the aerophones, the idiophones, the membranophones, and the chordophones (Wang, Y. T., & Anastopoulou, 2020). As shown in Figure 3, the classification and typical representative of four kinds of musical instruments are given.

Figure 3 -Classification of world national music instruments
The different music elements, including national music in music creation, enrich the forms and connotations of popular music. Therefore, the development of national music is a kind of mutual influence and integration of multi-national cultural identity and historical development at the musical level. Different national music in different regions has different forms and connotations, expressing the unique music forms of different national groups. This makes the forms and types of national music more colorful. The cultural background and development history of national groups in each region is different, forming a variety of music genres, and different music carriers together constitute their national music elements. Different music elements gradually form a more diverse world of national music through the gradual integration of culture (Wallach, 2019; Lee, C. K., & Lee, S. S, 2016). As shown in Figure 4, typical forms of different national music in some areas are given. The world's national music-cultural circles have experienced long historical changes and has formed regional ecological relations with various styles. From the history and cultural perspective, a widespread music-cultural circle is represented by core instruments.
Taking primary musical instruments as the identification of establishing a music-cultural circle division can achieve the classification and interpretation of iconic musical instruments (Nie, 2014). By classifying the world's national music-cultural circle based on the musical instrument category, ten major music-cultural circle can be sorted out, as shown in Figure 5. Among them, in Asia, due to its long history of cultural and historical development, there are relatively many music-cultural circle, with a total of five different music-cultural circle; In addition, there is one music-cultural circle in Europe, North America, Latin America, Africa, and Oceania. Therefore, combined with the distribution of the world music-cultural circle, it can also be seen that the origin and development of music also depend on the continuous precipitation and integration of culture and history.
Figure 5 -Distribution of ten traditional national music-cultural circles in the world In addition, according to the music types and the sound systems attached to them, different music-cultural circles can further compare the music-cultural phenomena of their local areas or national styles, from which we can also find the geographical route and temporal logic of the cultural and historical evolution of different music circles. In order to further analyze the musical culture and historical development of different musiccultural circles, table 1 shows the types of musical instruments and typical musical instruments used in the world's top ten music-cultural circles. Among the five national music-cultural circles distributed in Asia, although four types of musical instruments are involved, the region is still dominated by stringing instruments and body singing instruments, and the types of musical instruments in other music-cultural circles are relatively more extensive. From another perspective, it also reflects specific differences in the forms of expression and the use of musical instruments among national music formed by different cultural and historical backgrounds. Therefore, the analysis of the development of national music needs a comprehensive analysis and research combined with the background of its cultural and historical development. At the same time, it needs to consider the impact of integrating multiple cultures and history to lay a foundation for a comprehensive understanding of the origin and development of national music. Table 1 -Main musical instrument types and typical instruments in the ten major music-cultural circles (Su, F, 2015;Chambers, 2013)  In addition, through the national music in different periods, we can not only understand the social changes in different periods and the spiritual outlook of people at that time. At the same time, as an indispensable element of people's spiritual sustenance, national music has formed a complete set of music systems with regional characteristics and appeal after long-term development (Huihua, L., 2016; Yu, C., 2022). Based on the development of Chinese national music history and culture, Figure 6 shows the history of the evolution of musical instruments in the development of Chinese national music.

Figure 6 -Evolution history of Chinese national musical instruments (Representative instruments)
The development of the history of Chinese national music and the development of the world's national music also complement each other. Traditional national music is based on local culture. It has absorbed some other countries' national music characteristics in the development process. After continuous integration, it has become the driving force for national music's continuous updating and progress (Di, H., 2018). At the same time, it has also formed a unique national musical instrument performance style. As a multi-national country, China has a wide range of foundations and sources for developing and spreading national music, especially the integration and development of modern national music and multiple music, which can absorb more different innovative elements and form more national music with its characteristics. Table 2 shows traditional musical instruments in some Chinese national music works are given. Culture and history of popular music Popular music initially originated from the American music BLUSE in the late nineteenth Century and then influenced by cultural and historical development, it began to evolve and update gradually. Through continuous integration and development, it has formed modern popular music that is now widely accepted (Hausfeld, Disbergen, Valente, Zatorre, & Formisano, 2021). The original formation of popular music was for commercial profit. So far, popular music has formed a variety of style characteristics. As an abstract cultural art, some upper-class people can only contact popular music in the initial stage. However, thanks to the advent of industrialization, popular music has also become one of the cultures that ordinary people can enjoy. Therefore, popular music can also be seen as the product of the industrial revolution. Figure 7 summarizes the cultural background and historical evolution of the origin and development of popular music.

Source: Baidu Encyclopedia
By analyzing the culture and history of the emergence of popular music, it can be found that popular music is a popular and widely circulated form of music. The reason why popular music can continuously develop and innovate is because of its characteristics (Fang, X., 2019). Firstly, popular music has a certain degree of novelty. The creation of popular music should be in line with the psychological and spiritual needs of the audience, which can better meet people's curiosity and exploration psychology and stimulate more spiritual internal needs; Secondly, popular music has a specific commercial value, and its creative purpose is to obtain more economic value; Thirdly, compared to other music, popular music has a strong popularity, with more straightforward melodies and a moderate range. The accompaniment and harmony are relatively simple, making it easier to understand and accept. Modern popular music mainly covers Blues, Jazz, Light music, Tango, Swing, Waltz, Rock and roll, as well as the evolution of certain styles of popular music, such as Latin, rap, New age, and the fusion of various genres of music. As shown in Figure 8, the main manifestations of some modern pop music are presented. The form and content of popular music are closely related to people's history, culture, and life. It is deeply loved by people in a certain period, showing the characteristics of life and entertainment. It can meet the needs of the audience on a spiritual level, so it is also known as "popular music." Various types of popular music also bring more music enjoyment to the audience. Different types of popular music have different characteristics and musical instruments due to the differences in how they express emotion. Table 3 shows the characteristics of some main types of popular music and typical musical instruments. The progress of audio processing technology has also promoted the development of popular music at a higher level, which can achieve the needs of audience diversity. The emergence of new musical instruments in the electronic synthesizer category has broken the dominance of sound. While playing an alternative role, it can also create extraordinary sound. Highly developed digital audio technology can simulate the voice that breaks through the limitation of human imagination, bringing more abundant potential and more possibilities to creating popular music (Shan, W., 2022;Yue, S. & Qiang, L., 2016). In popular music, rap music in recent years is mainly in rhyme. Compared with traditional popular music, it focuses more on the creators' ability to play on the spot and control the rhythm. In the traditional Blues Jazz Light music Tango Dance Waltz Rock and Roll Modern popular music sense, rap music mainly appears in the form of content containing irony; at the same time, it is a kind of music with offensive language. Later, with the progress of society, it developed melody rap. In the new era, the emergence of electronic voice changers has further raised the upper limit of the development of rap music, making the original flexible rap music form and content more diverse. The application of modern electronic digital technology in popular music enriches the music form and further promotes the faster development and spread of popular music.

HISTORICAL INTEGRATION BY CROSSING THE BORDER
Cultural identity of national music and popular music The cultural identity of national and popular music should identify with the historical and cultural characteristics of music works and do not need to be rigid in the inherent form and music concept. Cultural identity needs the simultaneous existence of two kinds of music culture. Through mutual absorption and integration, we can better understand ourselves. For national music, after establishing the ownership of its own music culture, establishing the cultural differences between itself and popular music is also an essential part of music's cultural identity. There are two aspects of the meaning of national music and widespread music culture recognition. One is to confirm cultural subjectivity, a process of seeking common ground. The other is to grasp the differences between national and popular music, which is a process of seeking differences. This is mainly reflected in the cognitive level of national and popular music culture. The culture of national music is a symbol of self-identity based on its differences, which becomes a cultural symbol different from popular music. The essence of nationality is the uniqueness of music culture in the process of multi-cultural comparison. Therefore, in the cultural identity of national music and popular music, national characteristics are an essential foundation for discovering historical culture and aesthetic value (Ni, Y., 2021).
Through the analysis of the historical and cultural background of the origin and development of national music and popular music, it can be found that both the form and the connotation of the two in the communication process have appeared in the trend of cross-border and mutual integration. National music is an essential element and means of expressing traditional national art. In order to make traditional national art continue to inherit and develop, the development of national music has also been a concern for music creators. In order to meet the development of the times and the change of aesthetic needs, it is an ongoing situation and an inevitable trend to integrate national music elements into popular music. In continuous reform and innovation, national music has realized its cultural connotation's continuous improvement and innovation through continuous reference and integration of modern popular music creation techniques [31]. The integration of traditional national music and popular music makes not only traditional national music loved and accepted by more and more people but also popular music. It will develop more diversified based on absorbing national culture, which is also the internal driving force for identifying and integrating national and popular music across the border. Figure 9 summarizes the importance of cultural identity and the historical integration of national music and popular music to music diversification. Integrating the development history and respective cultures of national music and popular music can create a diversified modern music mode with unique charm based on absorbing the traditional characteristics of national music (Yuqi, B, 2022). In the process of mutual integration, three ways can be used: one is in the creation process of popular music, combining the characteristics of popular music with the traditional cultural characteristics of traditional national music, and enriching the creation form and music connotation of popular music, to broaden the transmission channels of national music; The second is to realize the mutual reference and supplement of traditional national music and popular music instruments. Musical instruments are the most crucial primary carrier of music performance and the specific performance of music culture and historical inheritance. Through the combination of the two instruments, they can have more diverse forms of expression at the musical instrument level, thus enriching the cultural connotation of national music and popular music and achieving the border crossing between the two, Promoting the deep integration of the two at the historical and cultural level; The third is to integrate the performance characteristics of national music and popular music, which can not only increase the rich cultural heritage of popular music but also more easily gain the recognition of audiences of different ages, to promote the rapid development of popular music and national music.

Impacts of integration
Cultural and historical reference and integration can promote the rapid development of national and popular music. In creating modern popular music, adding some elements of national music can enrich the cultural connotation of modern popular music and improve the public recognition of national music. In addition, the integration of popular music and national music can change the inherent form of traditional national music, promote the rapid update and iterative development of national music, change the transmission form of traditional national music with the characteristics of popular music, give full play to the characteristics of their national music. Integrating national music and popular music can also increase the enrichment of popular music content and inject more substantial vitality into popular music. National music is a characteristic music based on the traditional culture of various national groups. Integrating national music and popular music can give popular music full play to its advantages and reflect the different characteristics of different music, laying a more meaningful foundation for the spread of national music and popular music and communication under different historical and cultural backgrounds.
With the rapid development of society, integrating different elements of national music into popular music is an essential driving force to promote the development of modern popular music, which can make the cultural connotation of popular music more full. Under the background of the rapid development and spread of different types of music, the border crossing of traditional national and popular music has become an inevitable trend of the integration and development of the two. It also promotes the rapid development of popular music and national music itself, providing more ways and means for disseminating traditional culture and history in national music and the popularization of modern culture in popular music.

CONCLUSION
By analyzing the origin and development stage of national music and popular music, this paper summarizes the different types and characteristics of the two and the critical role of music in human emotional expression. At the same time, it explores the distribution of different music cultures in the world. Based on this, from the perspective of cultural identity and historical integration, this paper further explores national and popular music's role in promoting.
Strengthening the cultural identity and historical integration of national music and popular music, and realizing the border between the two, can not only achieve the diversification of music forms but also enrich the connotation of popular and national music. From the perspective of cultural identity and historical integration, popular music and national music are integrated, which can not only change the inherent form of national music, promote the rapid update and development of national music, but also provide support for the further enrichment of the cultural connotation of popular music, and further promote the mutual reference between popular music and national music. The integration of national and popular music can give full play to the advantages of the two and show the development of culture and history in a more diversified music form after integration.