Heat Check Roundup: Smino, Ayra Starr, Ghais Guevara and more Enlarge this image toggle caption Vivien Killilea/Getty Images for Interscope Vivien Killilea/Getty Images for Interscope The Heat Check playlist is your source for new music from around the worlds of hip-hop and R&B with an emphasis on bubbling, undiscovered and under-the-radar acts. — Gabby Bulgarelli YouTube Ayra Starr, "Rush" Once …