Tayla Parx uses life's everyday dramas as fodder for her always-relatable pop songs: Consider Alicia Keys' tropical-flavored “In Common,” about a woman worried her new partner might be as “messed up” as she is, or Ariana Grande's “My Everything,” a brittle piano ballad that mourns a great lost love. She also helped craft Mariah Carey's swaggeringly confident breakup anthem “Infinity,” which is powered by euphoric strings and brass.