Swift and Grammer

TAYLOR’S GRAMMER LESSON: Taylor Swift, who has not only cited Andy Grammer as one of her favorite new songwriters, but also sported some of the lyrics to the S-Curve artist’s hit, “Keep Your Head Up” on her left arm, was joined by the singer on-stage in Nashville to perform the song as a duet for over 20,000 screaming fans who sang along to every word. Check out the performance below. (9/19p)