We admit having never heard or seen that word before: sackbut. It sounds full of promise, definitely. Turns out it's a medieval trombone, and it will be heard this weekend at a few choice concerts.

The shows' themes are "1508," as in 500 year ago, which is when Heinrich Isaac composed. Heinrich was also Franco-Flemish. (And it's for guys like that that Belgium was invented.) He and Josquin Desprez are the forefathers of a polyphonic vocal music school in the early 1500s. This is a period that's often overlooked in the traditional classical repertory, but it sounds, in our limited exposure to it, surprisingly relevant and contemporary.

We're always happy when people stretch that staid classical repertory on both ends, and celebrate Heinrich or, say, Messiaen's 100th anniversary. We're always happy to mention local music groups too: expect great performances by Artists' Vocal Ensemble (AVE, a professional choral ensemble), and Whole Noyse, a wind band playing early music on period instruments, which includes the curtal and the sackbut. Both groups hails from the Bay Area.

Concerts are Friday, 8 p.m., at St. Ignatius, right by the USF campus; Saturday, 8 p.m., at St Mark's in Berkeley; and Sunday, 5:30 p.m. in Lafayette. Addresses, box office, and further details? Go here. That's a Catholic, an Episcopal, and a Presbyterian church -- adorably ecumenical, yes? It's only missing a synagogue entering a bar to turn it into a bad joke.