Aiko Shimada, a Tokyo native who lives in Seattle, sings in a bell-clear voice, in Japanese and in English. Her music is an adventurous, fluid and exquisitely ear-friendly blend of chamber pop, lower Manhattan jazz and textural forms; she’s recorded for John Zorn’s Tzadik Records and her own Bera label. Shimada and her combo Gibbous Moon will join locally based composer/vocalist Percy Howard and San Francisco singer-pianist Jill Tracy at 9 p.m. this Wednesday, May 1, at Old Ironsides, 1901 S St., for an evening of music unlike, well, most of the stuff Old Ironsides books. Door charge is $8. At any rate, it looks like the kind of show you’ll kick yourself for missing after the fact, so here’s your gentle reminder.