 Some suggest "What's Shakin' " started as "The Electric Blues Project", a follow-up to the 1964 compilation; however, Elektra founder Jac Holzman has stated "it was simply unreleased material that was available to us".Shortly after signing with Elektra, Paul Butterfield and band recorded an album's worth of songs which producer Paul A. Rothchild felt did not live up to the band's potential.Five of these tracks were chosen for "What's Shakin' ".