Sweet Water, Saturday, September 30, at the Bluebird Theater, has one of those biographies you've read a million damn times over the past several years: It's a quartet whose members were raised in Seattle, where they hung out with the guys in Soundgarden and Mother Love Bone, listened to a lot of punk albums and participated in the creation of the sound people are still calling grunge. Ho-hum. But what's more interesting to report is that Sweet Water seems to be turning into a pretty entertaining group. Unlike its generic major-label debut, this year's Superfriends (on East West/EEG) sports a handful of memorable, hooky tunes (particularly the single "Superstar") and enough snotty personality to differentiate the act from the approximately 2 million combos with the same history. Miracles can happen.