A Heron Oblivion moment — there’s a powerful one in nearly every track, so a representative one — comes about two-thirds through a track called “Rama,” with a crawling tempo and huge dynamic shifts. By this point, there’s been two ecstatic choruses amid restful verses, and one wild, expressive, Neil Young-like guitar solo. The song dwindles down for about 25 seconds, or eight bars, of Ms. Baird’s slow, quiet rhythm alone, played on bass drum and snare. It’s a long enough stretch to signal that something new is coming, something opposite and something big; it will have to be big enough to redeem that ominous lead-in. It does, and it is.