There are a few conservative musicians:
Ted Nugent
Sammy Hagar
Wayne Newton
Toby Keith
Charlie Daniels
Loretta Lynn
C.C. DeVille (guitarist from Poison)
One of the Ramones (can't remember which)
James Hetfield
Johnny Ramone.
You can add The Vandals to that list.
Also at least one member of the Smithereens and Michael Graves from the Misfits.
The Vandals have been a bit more prominent with the young people in their support of President Bush.