L.A.’s Mei switches up the tempo in his new single “Frankenstein,” via simple acoustic guitar strums, vocal ascents, and a charged-up passion. Where Mei’s indie-pop summer single “Rudimental” displayed his vocal versatility with switches from passionate croons to confident and sharper rides of the beat that led to full choruses powered by synth ambiances, “Frankenstein” keeps it bare, yet just as daring. Melancholic, and ultimately hopeful, “Frankenstein” has an obvious heart, a red mood to sink to, completely; stream “Frankenstein” below for a warm transition from warm days to cooler evenings. - René Cobar