The frontman of bands Tool, A Perfect Circle and Puscifer has a successful vineyard and winery, Caduceus Cellars.
All three were plenty famous singers before taking on judging on the long-running "American Idol."
The late half of Sonny & Cher was mayor of Palm Springs and was later elected to the U.S. House of Representatives.
After NSYNC and a solo career, Timberlake began starring in films. He has more than a dozen roles under his belt so far.
The No Doubt frontwoman and solo singer — oh, and Blake Shelton's girlfriend — has a fashion line called L.A.M.B.
The singer bought a South African diamond mine in 2006.
The guitarist of Queen pursued a doctorate in astrophysics but gave it up when his rock band got super famous. He went back and finished his Ph.D. in 2007 and has since collaborated with NASA.