How do you arrange a song? What is an arrangement based on?

It is the expansion of the musical expression without affecting the main melody and content of the original song. In modern music, especially pop music, the composer and the arranger are often two people, because many composers only have a grasp of the melody and inspiration, while the arranger has more skills in how to reflect the melody. To put it simply, the composer gives the skeleton, while the arranger gives the flesh and blood. Nowadays, in the era of digital music, many sounds are non-physical or reprocessed, which requires the composer to have a good understanding of arranging in order to achieve more sounds and effects. For musical works that already have a complete composition (such as more traditional symphonies, or other songs and pure music works that already have a complete composition of all the voices, etc.), the arrangement is only a grasp of the timbre and control of the soundstage. For musical works in which electronic sounds and special effects play a dominant role (e.g., electronic symphonies similar to Hollywood soundtracks, picture music, etc.), composing alone includes arranging. Arranging, in fact, is to use a variety of timbres to show your musical work and your creative intention to the audience, it is easy to say, but it will be a lifelong research project for any composer, because arranging is actually the second creation of music, is the further perfection of the original musical ideas and artistic sublimation. How to make a better arrangement for a song requires the support of music theory and instrument performance as well as acoustics and other aspects of knowledge, all factors are indispensable.　However, the theoretical things we can get from the books, but the instrument performance knowledge, only you through practice, recognize and then practice and recognize again and again repeatedly to gradually deepen the understanding of various instruments. Many of our friends in the love and pursuit of music, very much want to turn their own melody into an all-round display of their creative intent of the three-dimensional sound, but due to the lack of certain music theory and the lack of learning and understanding of the performance of the instrument to be used, based on a single wave of enthusiasm blindly on the horse, the result is that half a day's effort to make things not only other people are not satisfied, and even their own are not satisfied. This kind of thing is not only in the body of amateur musicians, that is, professional musicians work is also very cautious, although they are not like us often out of the "waste products", but they are in the work of others before handing over after repeated audio and visual, repeated modifications. Only then can they hand over the work satisfactorily.　Different musical works of the arrangement is not the same, the use of musical instruments are not the same, in addition to the style of the musical works must also be arranged to make the appropriate treatment, such as orchestral music should be appropriately heavier, the voice should be thicker, and general light music and pop songs need to be lighter, in order to make the singer's voice is more prominent, these specific requirements will affect the music of the arrangement. All we can say is that different situations are handled differently. Arranging work is complex and hard, I said that these are some friends who will not arrange music to have some knowledge of arranging, in order to arrange a good song must master a certain amount of professional knowledge, no matter whether you are into the school to worship or amateur learning, from the beginning of the study of the song practice, and then learn some of the harmonic and some polyphonic music foundation, and then instrumental method, etc., which are the basic knowledge of the composition, can not be ignored in all aspects of knowledge to support the role of arranging. The first thing you need to do is to learn how to make your own music, and then you need to learn how to make your own music.