The biggest bargain for San Diego’s music fans this month is the three-day Bayfair 2012 Air National Guard Races taking place Sept. 14-16 on Mission Bay. In addition to the thunderboat races, an eclectic mix of 22 bands will perform throughout the weekend in the vendors’ area at East Vacation Island. While it does cost to view the races on Fiesta Island, this location and all the music is free. Highlights from throughout the weekend include blues songstress Mercedes Moore, keyboard-based indie rock from Carpenter, and singer-songwriter Sara Groban. But there is no shortage of great music to be seen and heard at this event. • Bayfair 2012 musical entertainment takes place between Friday, Sept. 14 and Sunday, Sept. 16 at East Vacation Island. Friday and Saturday shows run from 1 to 10 p.m.; Sunday shows take place from 10 a.m. to 3 p.m. Free. www.sandiegobayfair.org.