Firstly, brass instruments were used in early middle age for communication at wars and hunting and then they were used king’s and leader’s welcoming ceremony. When brass instruments were used with woodwinds and strings for entertainment music, human beings needed differences on instruments structure. At that age, music was starting to develop and with this progress people thought, sliding trumpet’s tessitura was insufficient. For that reason, in XV. Century, trombone was improved which tessitura’s had middle and bass octave. First of all, people used trombone for religious music and after that they used trombone for court music and other activities too. In XIX. Century, the thought of using trombone in religious music was forgotten and people started to use trombone in operas and in symphonies. Ending of XIX. Century and starting of XX. Century, trombone started to be a very popular instrument and also people organized solo concerts in Leipzig. At the same time, people made competitions for composers to compose solo pieces for trombone in Paris Conservatorium and with this solo pieces trombone began to be popular instrument in America too. All these incidents provide trombone for being a solo instrument. Besides, in Europe and in America lots of composers compose solo pieces for trombone in different styles. Thus, trombone was precondition in solo instruments.