Joe Lally should need no introduction. As one half of one of the most rock-solid and inventive rhythm sections in rock and roll, he spent the better part of two decades playing the part of unshakeable anchor for Fugazi’s storms of dueling guitars. His fluid, rolling bass lines have been often imitated, and, in one case, appropriated for the unlikely purpose of rallying fans at sporting events.

With his former band in the midst of a very long, and very indefinite hiatus, Lally found himself with a whole lot of those bass lines and nowhere to put them. The purpose he did finally find for them was in an album of his own, released on Dischord Records late last year, called There to Here. If there are surprises to be found on the record, they are in the near skeletal arrangements, centered around Lally’s bass, vocals, and minimal percussion, with bare guitar flourishes added here and there. One song even dispenses with instruments altogether, as Lally delivers an earnest a cappella testimony on political doublespeak.

At the Black Cat backstage last week, it becomes apparent that the songs as they appear on record are really blueprints of a sort. They exist as an end in themselves, but they also are a framework for improvisation and interpretation, Lally’s bass providing the iron girders for other musicians to build on as they see fit. Like a jazz bandleader, Lally is able to tour with a ton of different musicians, and find new ways of playing his songs with every group. On Monday, his band was comprised of the Oberlin College-based Capillary Action. Their own show, which preceded Lally’s, revealed them to be an insanely talented instrumental ensemble that would have done Frank Zappa proud, switching tempo and genre on a dime as they gave the illusion of riding the cacophonous edge of disaster. When they changed roles to become Lally’s backing band, they faded into the background, displaying restrained musicianship, allowing Lally’s soft voice and lyrical bass to remain in the foreground as they filled in the gaps.

The sum total is a project that demands to be heard live, and heard live multiple times. Lally’s songwriting is elegant in its economy, and has an eerie beauty in the simple vocal melodies his bass winds its way in and around. But hearing the same song interpreted differently by whichever musicians Lally brings with him on any given tour is just as fascinating as the songs are enjoyable.