It was cold and rainy outside the Somerville Theatre a week ago Thursday, and inside the moviehouse local MC Mr. Lif was struggling to warm up the crowd. “I know you weren’t expecting to hear beats and lyrics tonight,” he quipped early on in his set, drawing attention to the incongruity of a triple bill that featured Lif paired with Atlanta-based producer and beatmaker Prefuse 73 opening for Japanese electronica producer Nobukazu Takemura and Chicago post-rockers Tortoise.

Lif eventually prevailed, winning over the sold-out room with his clever pop-culture references (“Synthesis like photo/Africa like Toto”), jovial taunts (“Y’all sound like the emphysema club!”), and head-spinning freestyles. He performed alongside Prefuse 73 (a/k/a Scott Herren), and their 30-minute set pointed toward a new rap æsthetic that matches dense hip-hop lyricism with sputtering, glitchy beats.

Sitting behind matching laptops, Takemura and partner Aki Tsuyoki served up 30 minutes of experimental electronica that veered from goofy vocoder-laced trip-hop to fusionoid drum ’n’ bass to buzzy and crunchy abstractions. The series of visual productions that accompanied the set made up for the lack of physical motion on stage, but I’m not convinced that the duo were doing anything more than sending e-mail.

Just as the anticipatory clapping and hooting reached a fever pitch, the five members of Tortoise ambled on stage. Greeted with a roar of approval usually reserved for full-on rock stars, the Chicago-based quintet returned the favor by delivering a gracious 90-minute set (including two encores) of enveloping instrumental music. Drawing heavily on their latest, Standards (Thrill Jockey), Tortoise showed how they’ve grown from their beginnings as minimalist, post-punk reactionaries into masters at synthesizing their hipster influences (krautrock, contemporary classical, dub, techno) into a holistic sound that never falls into cut-and-paste collage or mannered experimentalism. And though they were dwarfed by all the instruments on stage (two drum sets, two marimbas, two basses, a guitar, and an assortment of keyboards and electronic gadgets), the game of musical chairs that accompanied every song never impeded the flow of music. Tying everything together was a sense of melodic and rhythmic optimism — the folksy guitar melody of “Swing from the Gutters,” the open-road, cruise-control groove of “Djed” — that is, like Tortoise, indelibly and uniquely American.