Memphis natives Magic Kids burst with the wide-eyed optimism of an American Bandstand montage. Their lush orchestrations and omnipresent background vocals transition from sunshine rock to nostalgic ballads, both worthy of a dance at Homecoming. “Summer” opens with a full-stringed prologue narrated by the soft ooh’s of a cardigan-clad girl group. They steer an old-school Schwinn along a California pier, lending an ear or six as lead singer Bennett Foster croons wistfully for a love gone by. Subtle tympani rolls mark shifts in tone that break from the sad nostalgia, attempting a new optimism for a few measures before the clouds roll in again. A peppier selection, “Good to Be” zips through two minutes of joy and fanfare. Like a musical flash mob, it frolics and shimmies with abandon. The beat surges like Fosse hands and the violins pivot on sharp slides and plucks. As low horns hula-hoop around the sha-la-la vocal choreography, Magic Kids declare that a celebration for no good reason is reason plenty. Dig out your class ring and go steady with the gang at Middle East Downstairs, July 25 at 9 p.m.