In cars and in kitchens and around old-time music festival campfires, Heather Summers and Anna Krippenstaple have been singing together for ten years. Born three days apart - not blood kin, but hatched from neighboring eggs - their voices lock together with a Sara and Maybelle Carter or Everly Brothers sympathetic vibration. It's a sonic convergence that contains more than the individual notes the two are singing - a Sacred Harp "hollow square" where chords are made from the space between the notes. This is a mysterious thing, like splitting an atom or finding infinity in the distance from one to zero. The Other Years is their debut album.