The one thing I didn’t expect out of Swing Lo Magellan was to find out Dirty Projectors have a classic rock side in the first song “Offspring are Blank.” This banging of heads is but a dalliance, as the group settles into an R&B deconstruction flavored with the Andrew Sisters harmonies of Amber Coffman and Angel Deradoorian and bandleader Dave Longstreth’s spaghetti-wired vocal lines.

Swing Lo Magellan may be their least weird record. The intricacy of those songs are less the result of studio meticulousness then they are manifestations of Longstreth’s pursuit for perfection. Where this created dizzying heights on 2009s Bitte Orca and puzzling stretches of cosmos on 2010’s Mount Wittenberg Orca, their collaboration with Björk, Swing Lo Magellan is practically mellow.

The title track is sylvan enough to have emerged out of a Bleecker Street coffee house. The lead-off single “Gun Has No Trigger” possesses the easy airless glide of contemporary R&B with little of the histrionics. “Just from Chevron” could be a demo from Fleetwood Mac’s Rumours until the beats get discordant half way through. Longstreth himself sings more like a subdued Thomas Dolby than an amphetaminated David Byrne on the record.

Dirty Projectors can bring it. They are a sweaty, mostrous melody engine onstage, each member looking to be operating far past capacity, enrapt in some indie rock version of a runner’s high. These intricate tunes become thunderclaps, so maybe this most pensive of bands might just ride the lightning into the House of Blues and shatter all expectations.

WTUL Presents Dirty Projectors with Wye Oak at the House of Blues, Saturday, August 4, 2012, 8 p.m. Tickets $20-45.