Who knew post-rock indie pop would become such a crowded field? Austin trio Octopus Project has to work hard to put their own stamp on the subgenre, and they succeed convincingly on their third album, Hello, Avalanche, by adding dense, noisy guitar melodies and sweetly layered electronics. “Bees Been Struggling” is the album’s standout, a handclap-led instrumental that builds up with colorful piano chords, and down with buzzing guitars like a rafter dodging boulders through rapids. OP is at its best when the synths and drum machines are subtle buttresses around their superb acoustic strings, glockenspiels, and brass, as on the energetic “Ghost Moves.” The songs are better than ever, and it’s exciting to hear the band hitting its stride.