That was done with members of Sinatra's touring band. And, for a good cause!
Tremonti Sings Sinatra, which comes out May 27, is exactly what the title says. Tremonti put down his axe, put on a tailored suit and tie and recorded 14 Frank Sinatra songs last year, with a band comprised of more than a dozen of Sinatra’s touring musicians and led by his musical director Mike Smith. Proceeds will go to the National Down Syndrome Society, inspired by Tremonti’s one-year-old daughter Stella. The project also launches his Take A Chance For Charity initiative, which will challenge others in the public eye — musicians, athletes, actors, comedians — to step out of their comfort zones and make similar efforts for charity.