Since 1998, the Garfield Avenue Festival has shined a spotlight on local music while dishing out some of the best soul food in the city. After modest beginnings as a blues festival, the free event has grown each year, offering more food vendors, more street performers, more visual artists, more activities and demonstrations for young children and more music. The festival, which runs from noon to 8 p.m. on Saturday, July 19 on Garfield Avenue between 4th and 7th streets, now attracts about 15,000 people a year . . .