An ambient jazz-ish quartet explores the power of staying still. Nobody is making music with the quotient of both vibes and depth like guitarist Jeff Parker’s ETA IVtet. Recorded live in intimate clarity (the same general approach as 2024’s The Way Out of Easy), the two 20-ish-minute improvisations that make up Happy Today casually cover a vast amount of musical terrain. From the daydreamy beat tapes of Dilla and Doom to the repetitive patterns of early Philip Glass to the twinkling, peripheral qualities of a great Grateful Dead jam, they’re sophisticated in their attention but healing in their simplicity. It’s all great listening for both background and foreground, but it’s the first 10 minutes of “Happy Today” where the band reveals how powerful their subtlety can be, conjuring the static, mesmerizing quality of an aquarium full of jellies, somehow both moving and not.