"So let's make things physical," commands our favorite Canadian lesbian identical-twin-sister act, and that's "physical" in both the erotic and Olivia Newton-John senses. Yes, after six albums of terse, austere indie rock, Tegan and Sara have gone full-blown synth pop, fabulously. Mixing Katy Perry fizz with vintage, melancholy, Cars-style video-arcade bleepery and the duo's well-loved bleeding-diary lyrical forthrightness, Heartthrob flits from lust to rage to adoration to lovelorn depression and back with dizzyingly tuneful (and danceable!) ease. Best makeover since Tai in Clueless.