Just before Blue Hawaii switched on their drum machines and samplers Friday night at Arlene's Grocery, where they performed as part of a Canada-centric CMJ 2012 lineup organized by M for Montreal, the duo heard from one particularly excited male festival-goer. "Wooo!" he shouted, as if at a hockey game, much to the chagrin of Alex “Agor” Cowan, the button-pushing, knob-twirling silent partner to singer Raphaelle Standell-Preston. "Dude, it's not a 'Wooo!'" Cowan replied, if not mouthing those actual words -- Diffuser.fm might have just imagined them -- than certainly communicating them with the sourness of his expression.

Either way, he was right: Dude, it's not a "Wooo!" Blue Hawaii make lovely music that requires some concentration. The songs are spacious, engineered to maximize airflow between Standell-Preston's sighing vocals and the fluttering synth tones and depth-charge bass notes that make up most tracks, but they're not exactly minimal. Friday night, there was much to listen for and discover, particularly when things got really quiet, and it would have taken far less than a "Wooo!" to break the spell.

Other times, some fidgeting was forgivable, and in rare moments, dancing was not only appropriate but encouraged. Standell-Preston copped to being shy herself, but she urged the crowd to overcome its feelings of awkwardness and groove to Blue Hawaii's faster songs, which get rather house-y, albeit it in an artsy, Montreal-circa-now kind of way. After one such tune -- 'Daisy,' perhaps, from the duo's sophomore effort, 'Untogether,' due out Jan. 22 -- she prepped the audience for a return to more down-tempo fare, explaining the coming shift with words that warranted not a "Wooo!" but a "Duh!": "Slowness is very important."