Much of this is a happy Indian summer album – and with the turn the summer has taken here, we’re going to need something to keep our spirits up if this August steambath continues into September. Whatever the case, this is a mostly cheery, meticulously interwoven, smartly playful album of original Swedish string band instrumentals along with some imaginative reworkings of traditional material. Vasen’s guitarist Roger Tallroth uses an open tuning to maximize the incidence of ringing overtones, much in the same vein as Olov Johansson’s nyckelharpa (a Nordic autoharp with a set of reverberating sympathetic strings). The trio’s lead instrumentalist is viola player Mikael Marin, whose dynamically-charged playing ranges from pensively rustic to completely ecstatic.

A trio of dance numbers open the album, the third being Botanisten, a tribute to some Bay Area pals. It’s appealingly verdant and has some psychedelic tempo shifts if that means anything to you. Garageschottis is clever and shapeshifting as it builds tension. The title track, a tribute to a bunch of Indiana fans who campaigned to name a street in their hometown after the band, starts striking and minor-key before morphing into a dance. The best single cut on the cd is Absolutely Swedish, fast with eerie textures, sounding like there’s a wild mandolin solo going on. But it’s not! It’s Tallroth on the guitar, way up at the top of the fretboard, having fun as the nyckelharpa plinks in the background and the viola feels around for its footing.

Mordar Cajsas Polska (Killer Cajsa’s’Polka) takes its name from a friend of the band, fiddler Cajsa Ekstav who attacked some windows with her beer mug to to kill a swarm of wasps who’d invaded her studio. Ostensibly the results were not pretty. This isn’t nearly as murderous as the title implies, but it sways and spins and you can dance to it, as you can most of the album. Which wraps up with another series of upbeat dance numbers and finally the pensive Yoko, written about a Japanese manager (theirs?). It turns out somewhat pensive, reflective and ultimately very interesting. Happily, it’s not exasperated. Fans of JPP, Frigg and the rest of the A-list of Nordic string bands will love this; bluegrass fans ought to give this a test drive too, it’s a lot of fun. They’ll be on US tour starting September 18 in Boulder at the Boulder Theatre.