Since there seems to be a lot of devs posting here, I thought maybe it'd be useful to talk music too.
I'm a game music aficionado, composer and arranger. Weirdly, I actually got in to these games because of the music. I imported CAVE soundtracks before playing a CAVE game and even ended up becoming friends with Ryu Umemoto (RIP)—we talked at times about the importance of music to an intense genre like shoot 'em ups when he was composing Akai Katana. It's also pretty much the only genre where arrange soundtracks are really appreciated among players and composers alike. It's awesome that people like virt and our favorite YouTube reviewer Studio Mudprints have appeared on arrange soundtracks! With all this said, I hope that shmup devs take the soundtrack part seriously.
For me personally, I made some tracks for Llamasoft's TxK/Tempest 4000 and a lot of other games that aren't shmups. Also made tons of arrangements via OCReMix and otherwise back in the day, including a bunch of shmup remixes. You can hear a selection of related music I happened to have on Soundcloud here: https://soundcloud.com/anosou/sets/shmup-ish . And even though I don't do this full-time anymore, I'm always up for making music for shmups specifically.
Any other musicians around here? Let's make ourselves known to the dev community!