Singers and nonsingers rejoice as Main Street Gainesville’s karaoke summer kickoff is back for a second year. For those who love to sing for a crowd or those who just sing in the shower, New Vision Entertainment is bringing its lights, sounds and stage to the Downtown Gainesville square from 7-9 p.m. Friday. “Last year, it was such a hit and people had so much fun,” said Regina Mansfield of Main Street Gainesville.