Listening to the florid pianism of Art Tatum can be like eating rich chocolate truffles – you start to appreciate his records less than you should after the first half-dozen or so. But you don’t get that effect with parts of the Proper Records Tatum anthology because of the variety of contexts in which Tatum can be heard. The third disc in the Proper set begins with an item from a jam session recorded at the Metropolitan Opera House in 1944. Here Tatum is on good behavior, providing a tasteful accompaniment to a richly textured Coleman Hawkins reading of My Ideal. Next up is a series of trio recordings, with Tiny Grimes on guitar and Slam Stewart offering his charming simultaneously sung and bowed bass solos. (Did Stewart sing and play his solos just so that he would have a better chance of being heard on disc?) Parts of these performances are clearly pre-arranged ensembles, though they are intended to sound spontaneous – it makes me wonder just how spontaneous some of the solo work is as well. Given Tatum’s partial reliance on stereotypical piano figuration, the whole question of what is improvisation and what is not starts to become a gray area. The disc also includes the deservedly famous solo recordings from 1949 – Willow Weep for Me, Aunt Hagar’s Blues, and more. But there is also a rather bizarre live track, also from 1949. Tatum Pole Boogie hardly sounds like Tatum at all. The piece is in a down-home boogie-woogie idiom, like something Meade Lux Lewis might play. But the playing is rushed and, dare I say it, sloppy – instead of the usual solid and rounded Tatum sound, the runs are garbled, as though the pianist’s fingers were only skimming the surface of the keys. There are two spots where the continuity almost breaks down. It is thrilling in its way, but very atypical for Tatum.