When I have a look on Youtube about the music in noir style film, I find that there are plenty of pieces of Jazz music. That is Jazz noir music. Here is one of the Jazz noir music that I have found on Youtube:
The instruments that have used in this pieces that I can hear are the piano, the saxophone and the drums. I know that saxophone is a really important instrument in Jazz music. Its tone is low and it lasts quite long I think in this pieces. I think this non-diegetic sound is more likely to use when the character was in the bar or chat with the others.
But, Jazz music is not the main music to the classic era of film noir. It is more likely to use as a source music, which is the stuff that comes off jukeboxes, radios etc. in the scene.
Most of the music in film noir is modernistic orchestral music. But here, I just can find the modern noir songs. So here I give one of the songs:
