There was a wonderful subtlety about that performance. Heart were known in the beginning as "the Female Led Zeppelin" and indeed they covered lots of Zep songs in concert and albums, no to mention being heavily influenced by them. I saw Heart in '77 (damn I'm old) and they did "Rock and Roll" during that show. The steady building arrangement was amazing. Jason Bonham, son of the late Zep drummer John Bonham, wears a bowler hat, as you saw. I didn't think anything of that until the mass choir near the end is revealed wearing the same hats. John Bonham would occasionally wear one back in the day:



A wonderful tribute inside of a tribute, subtle and loving.