Surprise! The lineup for the Official Prince Tribute Concert Thursday night in St. Paul has become a bit of a revolving door.

Pop star/guitar hero John Mayer has officially dropped out, according to concert promoter Randy Levy.

"Change of schedule for him," Levy said late Tuesday night. "That's about all we know."

Mayer, who recently toured with the Grateful Dead spinoff dubbed Dead and Company, was something of a surprise in the first place. What was his connection to Prince? No one knew for sure.

His connection to the concert, though, was Irving Azoff, who manages Mayer, the Eagles, Fleetwood Mac, Christina Aguilera and others. Azoff was contacted by L. Londell McMillan, a special adviser to Prince's estate who was spearheading the concert when it was planned for U.S. Bank Stadium.

Now, however, the much-discussed salute to the late Prince will be held at Xcel Energy Center with Stevie Wonder, Chaka Khan, Aguilera, Morris Day & the Time, Judith Hill and many others.

After Wonder, Mayer was arguably the biggest name on the bill.

While Mayer exited, more performers were announced on Tuesday including ex-Pussycat Doll Nicole Scherzinger; Portuguese fado singer Ana Moura, who performed with Prince in Europe; former Prince band members Andre Cymone, Shelby J, Elisa Fiorello Dease, Kip Blackshire and Michael Phillips; and dancer Mayte Garcia, who was Prince's first wife.

Look for more updates on the concert . . .soon.