This five-CD box set from Mosaic documents Duke Ellington's least-known period, his two years on Capitol. Although thought of by some as his off years because of the absence of Johnny Hodges, the set serves as evidence that a great deal of viable music was created. The problem was basically one of the times themselves, coupled with weaknesses at Capitol and its approach to marketing jazz. Ellington's move to the label followed four frustrating years at Columbia Records, where he was kept out of the studio for 20 months by a combination of the musicians' union strike and the label's laziness, and then allowed to record two startlingly ambitious LPs, only to see his sales (in an era dominated by singers and novelty tunes) plummet. He felt the new label would be able to sell his records better than Columbia, but it wasn't to be -- Capitol, although an aggressive, upstart company, wasn't well focused on jazz. In fact, however, during this period, Ellington's orchestra had 11 distinctive soloists including four very different trumpeters (Clark Terry, Cat Anderson, Willie Cook, and Ray Nance), and they were playing and even writing good music. In addition, there's a well-known trio set (sounding better here than on Capitol's own reissue) that showcases Ellington's underrated piano playing. Toss in the original version of "Satin Doll" plus the unusual Ellington '55 album, and one has a highly enjoyable reissue that Duke Ellington fans should pick up immediately. Two other virtues of this set that fans should consider are the extraordinary sound quality and the thoroughness of the historical annotation. To properly appreciate all of Ellington's best work during the period covered by the Mosaic set, one should also grab hold of the Discovery Records reissue of those Reprise recordings, Symphonic Ellington.