Looking for information on movie scene music

Anyone out there able to help with some information on the following:

From the 1981 movie "THIEF" starring James Caan. There is a scene where James Caan goes into a bar and drags his wife outside. During the bar scene there is a group playing a session. Can any kind soul who knows the scene let us have any details of the group, title of the music they were playing, etc.

We know the overall theme music for the movie is by Tangerine Dream, but the music in this particular scene is not theirs.

Thanks in advance.

Regards, Richard