MUSIC It's a typical music-loving day at Aquarius Records when I call up the store's Irwin Swirnoff to talk about its 40th birthday and accompanying celebration. "There's always been some confusion about when the store started," says Swirnoff, after ringing up a few purchases, as the translucent sounds of Washed Out swirl from the AQ stereo. "There original owners were awesome, but stoned a lot, so they weren't sure if it was 1969 or 1970. Once we realized it was 1970, we decided to put on a birthday party, and we thought it would be great to have bands that reflect the passions of the store, from pop to heavier sounds and drone."

Aquarius rightly has a reputation for introducing musicians to wider audiences, so it's no surprise to hear that a variety of bands — Cali rockers the Mantles; purveyors of heavy Djenghis Khan and Pigs; space rockers Lumerians; Root Strata dream drifters Date Palms; and special Cali pop headliner Best Coast — answered the call. "It's one of those shows where you're not seeing five bands that sound alike, but five different ones that fall under the same roof," says Swirnoff. "Next year we hope to throw a benefit show because it is a hard time for record stores. Maybe it'll become an Aquarius tradition."

In the days when Windy Chien guided the ship, and in ever-flowering ways today, the diverse and innovative sounds at Aquarius have been generated by the musical passions of those who work there — and those who shop there. "We're blown away by our customers and their eclectic and wide-ranging tastes," says Swirnoff. "They might buy a disco comp, an esoteric album, and a girl group reissue all at the same time. There's a communal enthusiasm from the staff in the reviews that we write, and we're lucky to have customers who share that same kind of enthusiasm We live in a culture that likes to compartmentalize. But at the end of the day, good music is good music."

AQUARIUS RECORDS' 40THE BIRTHDAY SHOW

With Best Coast, the Mantles, Lumerians, Djenghis Khan, Date Palms, Pigs

Mon/25, 8 p.m.; $10

Cafe Du Nord

2170 Market, SF