“The borders of my mind can always be redrawn.” Even those who don’t consider themselves jam-band enthusiasts may share the sentiment from the group Stormy Chromer’s song “Redrawn,” after seeing the Ypsi-based band perform live. Drummer Amin Lanseur and bassist Ryan King were inspired to start the band in 2014 after attending a festival organized by that progenitor of jam bands, Umphrey’s McGee. Stormy Chromer’s lengthy, improvisational, and often instrumental numbers fit Umphrey’s template to a degree. But the band’s versatility and impressive musicianship add unique appeal.

Stormy Chromer’s members all have professional musical training, an unlikely precursor to playing their current instruments in a rock band. King has a degree in classical clarinet from U-M, while Lanseur took tuba and other music classes at EMU, where he met guitarist Spencer Hanson in jazz class. Guitarist Brendan Collins, too, has studied jazz and other musical topics at WCC.

Neither tuba nor clarinet is heard at a Stormy Chromer show, and the sound could only occasionally be described as jazz. But the players’ professional attention to detail is clear. The members frequently turn their heads to form a loose circle around Lanseur, who leads the band’s regular shifts in tempo and groove with his innovative and energetic drumming. Lanseur knows his instrument well, and he constantly adds graceful flourishes that add complexity to otherwise simple beats. Collins handles the lion’s share of the lead guitar work, employing a small army of pedals as he cycles from attention-grabbing blues solos to mellow, echoing arpeggios. Hanson adds colorful rhythm parts and some impressive leads of his own. And while the band’s sound isn’t bass-heavy, King flashes some funky chops in occasional solos.

The players’ diverse musical backgrounds also have engendered a loosey-goosey approach to genre that can be fascinating to behold. Their jams can run up to ten or fifteen minutes, shifting fluidly from groovy funk to mind-expanding prog drone to heavy-metal sludge to power-chord classic rock, all with impressive ease. Often they’ll throw in their original folk-inflected ballad “Virginia in Vermont,” with King and Lanseur singing pleasant harmony, for good measure. The covers that leaven their mostly original sets are similarly diverse, ranging from the Cranberries to Rush to Ann Arbor’s own Tally Hall. Where many jam bands play primarily funk or prog, those are just ingredients in Stormy Chromer’s delightful, danceable mix. If the band ever seems to be settling into a particular musical idiom, just keep that pencil ready at the borders of your mind and wait for the next intriguing shift.