Elvis' five Sun singles pioneered the blend of R&B and C&W that would characterize rockabilly music. For quite a few scholars, they remain not only Elvis' best singles, but the best rock & roll ever recorded. Claiming that Elvis made blues acceptable for the white market is not the whole picture; the singles usually teamed blues covers with country and pop ones, all made into rock & roll (at this point a term that barely existed) with the pulsing beat, slap-back echo, and Elvis' soaring, frenetic vocals. "That's All Right Mama," "Blue Moon of Kentucky," "Good Rockin' Tonight," "Baby Let's Play House," and "Mystery Train" remain core early rock classics.