With 2010’s Patagonian Rats, Tera Melos have bequeathed an opus. The Sacramento, Calif., indie-prog trio gets into some next-level math rock while tweaking its formula to sound more accessible than on previous recordings. The opening intro, “So Occult,” maps a melody for 35 seconds with sparse notes and whispered singing before “Kelly” rips the tune’s top off with explosive results. The refrain gets washed out in waves of sonic maelstroms and a chaotic flurry of modal notes. But it’s “The Skin Surf” where the band reveals a penchant for fusing infectious pop hooks with intricately charted time signatures and completely unpredictable arrangements. At eight and a half minutes long, “Trident Tail” provides an epic journey into the depths of the Tera Melos machine. With wonderfully disjointed fretboard meandering that contrasts with airtight changes during turbulent patterns, it all makes early Yes songs sound like nursery rhymes in comparison. Out of the eight extra bonus songs (almost an album’s worth), salient cuts include the algorithmic “Purple and Stripes” and the surprisingly mellow “Manar.”