Does anyone know the name of the song being played right after the scene where Michael and the Don tell Tom Hagen he's out? The song starts when Michael arrives in Vegas. Big Band type of song.

I'm guessing it's a little theme that Nino Rota wrote just for that brief scene-setter.

This is the best I could find:

"As Michael and his entourage arrive in Las Vegas, the music is glitzy, a swing rhythm that really evokes the Vegas vibe, and while the soundtrack lists this as ‘Music from Vegas’ by Nino Rota, I suspect this isn’t actually an original piece – more likely an arrangement of some other band music."