Valli is currently on his Frankie Valli & the Four Seasons: The Last Encores tour. Kravitz is mid-tour after his "Blue Electric Light" album released in May.

"Endless hits and still touring at 90 years young," said the Grammy-winning "Fly Away" singer-songwriter of Valli

Back in August, we reported that the singer Frankie Valli, 90, was seen seemingly struggling to lip sync during a concert. That, combined with his age, led to rumors that Valli is being ‘forced’ to keep performing by unknown forces.