Steampunk is a many-splendored thing (sorry Ms Suyin), touching many eras and ideaologies; similarly steampunk music is just as varied as the waistcoats on a steampunk model. Maybe you haven't heard of some of the following and you'd like to try them, or maybe you've heard of others you think we should listen to?
Clockwork Cabaret - A podcast rather than a band, this is the premier steampunk radio program, they're... mostly... kinda on topic a lot of the time. Episodes have a theme that's loosely observed from afar, and they play a mix of music broader than steampunk, but definitely entertaining. They also host steampunk New Years Eve parties, DJ at Dragon Con's alternate history track, and Emmet Davenport runs a steampunk themed coffee shop. I've found a lot of new music from this podcast.
A Halo Called Fred - Their tag line "the best guitar, bass, violin, and Tupperware band in the universe" may describe why I like them so much. Fun music, from the "step on a butterfly, change the future" logic of 'In an Alternate Reality' to the all inclusive nerd anthem of 'We Love You All', they're fun fun fun.
The Cog is Dead - Each song is its own little story or snapshot of a steampunk world. My son and I regularly sing "Danger on the Dancefloor" in the car, and the "Prepare for Adventure" really sets up the whole album.
The Electro Swingers - Reversing the trend of "new music in old styles", this takes old music and jazzes it up with electro.
Abney Park - Embracing the Steampunk Air Pirate to the nines, they've spawned games and books set in their post-apocalyptic universe. I really like "Steampunk Revolution" and I'm staring a "Whole Life Crisis" right in the face.
The Clockwork Dolls - The Dramatis Personae really feels like a collection of interwoven stories in song, with recurring characters, and a great listen from beginning to end. "Clockwork Maid" makes me think, but "No Guns Allowed In My Bar" is particularly rollicking.
Professor Elemental - One of the Chap-Hop greats out of the UK, soaring into the steampunk consciousness with "A Cup of Brown Joy" (I still prefer his original), he's also in comic form and youtube series form.
Sunday Driver - Asian steampunk, mixing colonial UK with the Asian continent. "Black Spider" is a good starter, and "Mechanical Angel" feels like fairies on the keyboard.
The Decemberists - I'm listening to the Decemberists less lately because they're definitely on the dark side of the Industrial Revolution. Revenge and horrors of life abound.
Frank Bennet - One of my great losses were his two original albums, because you can't get them anymore. They were made of Jazz covers of modern music - you could argue they're more Diesel punk than Steampunk, but bah. I like 'em. The cover of "Creep" sticks in the mind.
The Gregorian Masters of Chant - Flipping time maybe too far the other direction, modern songs performed in Gregorian Chant. I have a particular soft spot for "Bridge Over Troubled Waters".
The Mouldy Lovers - A local group I first heard at Prometheus Bound (steampunk nightclub). Very Romanian influenced, I like the "Tetris" one especially.
Mr B - One of the Chap-Hop greats out of the UK. Yes I repeated that title, as Professor Elemental and Mr B have had a joking "Rap Battle" that turned into competing complements and then a promise to join forces. I listen to Mr B slightly less now as I feel he embraces some of the less awesome aspects of Rap than the bonkers nature of Professor Elemental. "Straight out of Surrey" is great.
Unwoman - Singer with a wicked cello, saw her live at Steampunk Strides and bought a number of albums immediately. The covers in "Lemniscate" are great, I'm especially fond of "Beauty Over Industry" from another album
8in8 - A temporary band formed by Amanda Palmer, but the first song on the album is "Nikola Tesla" with a number of steampunk tropes. Fun.
Any more steampunk music suggestions?