For every summertime fling, there is a song that laments its fleeting passion and jubilation. The two vocalists harmonize lines like, “Splashing, laughing, loving, just like a fool / Was there an undertow when I pulled you close? Legend, who is the same age as Jones at 46, is more like her contemporary. “Her voice, soul and musicianship, her graceful presence are all undeniable,” said Legend in the same announcement. It comes as no surprise that Blue Note, a generation-spanning label steeped in history, would make this single its home.