Nat King Cole spent virtually all of his career with a contract from Capitol. (The classic Capitol Records tower, near Sunset & Vine in Hollywood, wasn't known as "the house that Nat built" for nothing.) But his earliest sides appeared on a range of labels, including, but not limited to, Decca, Keynote, and Mercury. (Aside from what's heard here, the King Cole Trio recorded dozens of effervescent songs between 1938 and 1941 for transcription services, music that has only rarely been commercially issued.) Riffin': The Decca, JATP, Keynote and Mercury Recordings puts a wrapper around a fair share of his non-Capitol sides, some of them early (Decca) and some of them live (JATP) and some of them as a sideman (complete with hilarious noms de plume) for Lester Young and others (Mercury). Best are the early King Cole Trio sides, from 1940-1941, when the group was still writing songs and delivering them with the energy and flair of a club act, making mini-masterpieces from off-the-cuff songs "I Like to Riff," "Call the Police," and "Stop! The Red Light's On." Novelties for sure, but novelties with tight group interplay that showed what small-group swing could do, along with bouncing solos from Cole's piano that earned him fame and influence far beyond what the singer of "Unforgettable" could have garnered. Also well-deserving of attention is his 1946 session with Lester Young (and drummer Buddy Rich) for a Mercury album that sees him giving Young the best accompaniment he would ever receive. The JATP sides cover a Jazz at the Philharmonic concert from 1944 where Cole's piano was heard (faintly) with a jam session including flamboyant, roof-raising solos from Les Paul, Illinois Jacquet, and J.J. Johnson, among others. (Cole's modesty in these circumstances is humbling.) This three-disc wrap-up isn't a unified set -- despite the material ranging only from 1936 to 1944 -- but it captures His Majesty in a range of circumstances; quite fitting for the man esteemed by jazz fans as one of the greatest pianists of all time, and by vocal fans as likely the best interpreter of popular song in the 20th century.