Even in this vinyl-happy town, Groove Merchant Records in the Lower Haight stands alone as a dealer of rare, vintage, and under-appreciated sounds on wax. The tiny shop has an international reputation for digging up awesome rhythms, so it's only natural that it also has a regular party every fifth Friday at Madrone. The night's headlining DJ is none other than Groove Merchant owner "Cool" Chris Veltri (pictured); other spinners include Jerry Nice, Vinnie Esparza, B. Cause, and Jon Blunck. It might be your best bet to hear the music that's moving the crew at one of the city's most interesting record stores. Groove Merchant's end-of-the-year party goes down Friday, Dec. 30, at Madrone Art Bar.