"Crossover" hits ("folk songs" that became rock-music-scene staples) happened now and again. One well-known example is the song "Hey Joe", copyrighted by folk artist Billy Roberts, and recorded by rock singer/guitarist Jimi Hendrix just as he was about to burst into stardom in 1967. The anthem "Woodstock," which was written and first sung by Joni Mitchell while her records were still nearly entirely acoustic and while she was labeled a "folk singer", became a hit single for Crosby, Stills, Nash & Young when the group recorded a full-on rock version.