On this day in 1972, the singer of Led Zeppelin seemed to be working on his Elvis Presley imitation, while his group was outselling the King. Presley's "Heartbreak Hotel" and "I Need Your Love Tonight" were among songs included in a rock 'n' roll medley toward the end of Zep's concert at the Baltimore Civic Theater. Plant used his higher singing range to pay tribute to his muse and do the songs justice.