Piano is my main instrument. I can play guitar and bass passably enough to get paid to do it. Accordion, yeah, because I was once a little kid, plus I got paid to play one once for an ad. Same with mandolin, though I haven't owned or played a mandolin in 20 years.
No one pays for harmonica - ever - and it's one of the 'verboten' instruments in ad world. But I can play the damn things if you want something bluesy. I learned to play it in case I ever get tossed into a jail cell in the Old West.
If you can play the pitched foot pedals on an organ, you're bona fide. I can do that. Big deal, right? I can program a synthesizer so it's not just an electric piano thingy with presets. That's the only thing about a synth that's different from other keyboards. But hey, if you're a synthesist and not just a 'keys' person, ya gotta know how to do it.
I tried to learn the flute. Learned some scales. Kept running out of breath. Never get serious about an instrument that makes you feel lightheaded to play, is my motto.
I have been paid to play percussion instruments. However, I'm a very crappy percussionist, and consider myself lucky that I can shake a shaker in time.