I thought first of Milt Hinton, but I guess the bass would be his least likely subject. The usual suspects for jazz portraiture have done plenty of bass *players*, of course, but usually with more focus on the musician than the instrument. Make your own decor, I'd say, so your instruments can look at their own portraits!
I play bass too, and I've found it's *very* challenging to get a photo of a stringed instrument that isn't a cliche. Ultra-shallow DOF looking down the strings at the bridge? Been done a thousand times. Tight crop of a violin corner and the upper part of an f-hole? Bow on strings with vibration blur? Ditto. I keep producing images that look like the dummy photo you'd get in a department-store frame.
I've never gotten serious about taking it on as a photo project, but it seems like a good one. Obviously the subject has potential.