If you zoom in a little on the of the members, you can see a little bit of the uniform. From what I can tell, they are sleeveless and colorful. I also picked up some kind of blue lining across the chest.
If you take 2016 for an example, they listed a number of musical selections that they did not play. They often do this. Some music they do play that is not listed and some music they do not play that is listed.
I have heard BD show and the Metropolis 1927 piece is heard in the show. Just because BD did not list Graham as a source of music does not mean anything. They do this a lot. Some pieces they play and some the don't.
This is my guess of their music Rep. :
City Noir by John Adams
A Symphony of Colors by Simon Dobson
Dream Catchers by Paul-Lovatt Cooper
Original Music by David Glyde
Natural Woman by Carole King
Laura by David Raksin
Harlem Nocturne by Earle Hagen