We don’t really know what Joel Hamilton means when he tells us via email that his latest one-man music project, Mechanical River, is “twirling through hyperspace at the speed of mud, leaving everything that has a mouth with the sharp taste of numbers and the smell of hugs.” But if hugs smell the way Mechanical River sounds, then someone needs to bottle that scent. It rocks.

As you may have guessed, Hamilton’s a hard musician to pin down. It’s not just because of his freedom with metaphor, although that’s certainly part of it. Hamilton doesn’t really like to define his music, which has changed and developed over the years from something that could easily be called alt-pop to a sound characterized by hints of country, electronic, folk, and indie rock.

That wide variety of influences is especially evident on his most recent release, Mechanical River’s Astral Castle, which features Hamilton singing and playing the keyboard, percussion, and a homemade cigar box guitar. On some of the tracks, the guitar adds a warm, homey contrast to the electronic sounds of the keyboard. But in its more synth-poppy moments, Astral Castle could have been inspired by a 1980s video game soundtrack — especially the instrumental “Ghost Crab,” which gives us the genius idea for a throwback arcade game in which crabs scuttle through a dry marshbed, avoiding being eaten and waving their little claws at each other in time to the music. Maybe we’ll let that one sit for a while.

Just as he is with musical genres, Hamilton is an egalitarian when it comes to instruments. “The exciting thing is, anything can be an instrument. And musical,” he says. “Fire. Ice. Sand. Balloons.” We don’t know if he’s played any of those instruments yet, but we do know he plays bass, banjo, and guitar in addition to the aforementioned keyboards, drums, and accordion. The accordion is the one instrument Hamilton is eager to talk about; he used it extensively on the 2010 album he released under his own name, Feels Like We’re Gonna Win. Along with Hamilton’s folksy, ethereal singing, the instrument’s melancholy hum is one of the most distinctive sounds on the record. “It’s such a beautiful and somber instrument,” Hamilton says. When we say it makes us think of France, he agrees — or maybe makes fun of us — saying, “You couldn’t be more right. The accordion parts are mostly all inspired and created by, for, to, and with the taste of French dressing … There are some French composers that use a lot of accordion and I really like the way they incorporate it into the music. There’s a lot of rhythm involved.”

Though you wouldn’t know it to talk to him, 2012 has been a kind of career explosion for Hamilton. He released the self-produced Astral Castle in May and spent the month of June touring. Then in September, he and Rachel Kate Gillon joined the Unchained Tour, the storytelling show featuring story-spinning superstars Neil Gaiman, Peter Aguero, and Edgar Oliver. Though the experience didn’t really affect his approach to music, he did enjoy his time both on the tour bus and on stage. “It was nice to be in an atmosphere where people were very much at the edge of their seat, hanging so dangerously onto every word that came off the stage,” he says.

As for what 2013 holds for Hamilton, he won’t give us specifics, so we can only guess. But if the past few years are anything to go by, we bet that the future holds even more deft juggling of bands, sound styles, and musical identities. Case in point: In addition to Mechanical River, he’s playing with garage punk-y band Boring Portals, whom Hamilton calls “psychedelic as fizz.”

For now though, Hamilton is traveling in Germany and his concerns are more immediate. “Right now I’m making sure the voltage conversion with this German plug won’t make my old Casiotone melt or explode,” he says. Other than that, he’s doing what he does best. “Lots of playing, lately, and listening. And some writing and recording.”

We couldn’t ask for anything more.