Robert Lamm announced last month that the former vocalist and bassist had agreed to play at the ceremony - but later apologised, saying that the invitation had been "emphatically declined."

Now Cetera has revealed the contents of an email that reads: "As a finale, we can walk onstage together one last time as a group, I'll strap on the bass, and we can do 25 Or 6 To 4 in the key of E. I believe it would make for one fantastic Hall of Fame moment and satisfy those who have always wanted some sort of reunion.