Unit 4 + 2 still gets airplay today thanks to "Concrete and Clay." The 1965 single which hit No. 1 on the U.K. Pop charts and No. 28 on the U.S. Hot 100, and inspired covers by everyone from Gary Lewis and the Playboys to They Might Be Giants (including Randy Edelman's hit revival in 1976). But there was more to the British pop band, as evidenced by RPM's double-CD anthology, Concrete and Clay: The Complete Recordings. The 43 tracks here hail from 1964-1969 and encompass two albums, an EP