The Dharma Wheel, Howlin Rain’s sixth studio album, begins with the sound of Scarlet Rivera’s violin—the same sound famously heard on Bob Dylan’s Rolling Thunder Revue tour. It’s a tip-off to the classic-rock vibe that permeates The Dharma Wheel, which finds Howlin Rain founder Ethan Miller embracing a polished and proggy full sound—a contrast to the raw energy of 2018’s The Alligator Bride. “Prelude,” the Pink Floyd-indebted instrumental that starts the record, sets the tone, patiently building into a noisy crescendo as the rest of the band drowns out Rivera’s violin. On the groove-based “Don’t Let the Tears,” the album’s other special guest makes his presence felt immediately. Those space-age synths are courtesy of Circles Around the Sun keyboardist Adam MacDougall, whose distinctive stamp pushes the album toward prog-rock excess. Clocking in at 52 minutes with just six songs (all of which exceed six minutes in length), The Dharma Wheel, which was originally conceived as a triple album, excels in that excess. Songs like “Under the Wheels” (a hooky classic rocker that shares a title with Howlin Rain’s last two live albums) and “Rotoscope” are allowed to breathe and build with album-length jams. On the latter, Miller and Daniel Cervantes’ twin guitar leads give way to an ambient jam led by bassist Jeff McElroy, who leaves space for MacDougall’s subtle textures. Rivera reappears for the lone ballad, “Annabelle,” one of Miller’s most affecting songs in recent memory: “Annabelle, I love you well,” he sings. “Come back to bed a while/ And stay a little longer in the ruins.” The centerpiece and coda of The Dharma Wheel is the 16-minute title track, a multi-part prog epic that reminds listeners just how far down the jamband rabbit hole Miller has gone since his Comets on Fire days.