Aly & AJ

Aly & AJ are the sisters Alyson and Amanda Michalka, from Southern California, who began recording as teenagers in the mid-2000s while also working as actors. Their early pop albums produced "Potential Breakup Song," still their best-known track, before the pair stepped back from music, released work briefly under the name 78violet, and eventually returned to the Aly & AJ billing.

The later records lean on layered sister harmonies, warm synthesizers and a widescreen, guitar-and-keyboard version of pop that draws on 1980s production. They write their own material and have released it independently, with the two voices close enough in timbre that the harmony lines often blur together.