The violins are the sopranos of the string section. There are more of them than any other instrument in the orchestra, so many, in fact that there are two sections and the first violins and second violins rarely play the same part. The violas play the inner voices in the harmony and many great composers, including Mozart and Brahms, enjoyed playing viola because they loved to be in the thick of the musical texture. The rich-toned cellos and double basses look after the bass line and provide the essential foundation for the music.