H.E.R. debuted a new song, “I Can’t Breathe,” which she wrote in response to the recent spate of police killings of unarmed black citizens and the swell of protests against police brutality and systemic racism. The musician shared the song during her performance on the iHeartRadio Living Room Concert Series.

H.E.R. opened her set with “I Can’t Breathe,” introducing the song by saying, “Just by the title, you know that it means something very, very kind of painful and very revealing… These lyrics were kind of...