Seattle’s The Head and the Heart play The Mountain’s sold-out Winter Warmth, Thursday at the WaMu Theater.Band: The Head and the HeartAlbum: iTunes SessionLabel: Sub PopRelease: Out NowLive in-studio-esque sessions rarely offer more than fan-only performances. But if you’re already sold on this band’s breed of smooth indie, then this one’s worth a listen.Disciples are treated to alternate renditions of favorites, and a pair of previously unreleased live staples — “When I Fall Asleep,” and “Ever Since” – and alternate versions of favorites from the band’s self-titled debut. Combined, it provides a tidy window into the band’s evolving sound. There’s an added helping of stomp here that was absent on their full-length debut, but has carried the band live.