Until the late 1990s, the recordings from Rudi Blesh's legendary 1947 This Is Jazz radio series have only been available in piecemeal and scattered fashion, with many of the performances never put out at all. Finally, in a series of two-CD sets, the complete shows have been getting released in chronological order by George Buck's Jazzology label. Volume Four is among the strongest in the series, reissuing the May 3, 10, 17 and 24 programs. Heard from are cornetist Wild Bill Davison (who is often quite inspired), trombonist George Brunies (in his prime), clarinetist Albert Nicholas, guitarist Danny Barker, bassist Pops Foster, either Baby Dodds or Freddy Moore on drums and either Joe Sullivan, Art Hodes or James P. Johnson on piano. On the first show, singer Coot Grant and vocalist/pianist Kid Socks Wilson guest on a few songs, while pianist/vocalist Kirby Walker is present on two songs (including a piano feature on "The Shout") during the May 10 episode. While the May 24 show has soprano saxophonist Sidney Bechet as a guest and James P. Johnson on piano for a tribute to Fats Waller, it is the May 17 program that finds the group really catching fire. Cornetist Johnny Glasel, who was just 16 at the time, is quite impressive on a hot version of "Shine." Davison, Hodes and company are quite joyous on "Original Dixieland One Step," "Hotter Than That," and "King Porter Stomp," and Brunies and Dodds take a surprise good-time vocal on "I Ain't Got Nobody." And since the other three shows are almost up to that level and Blesh's somewhat reactionary commentary about "real jazz" is fairly restrained, this twofer is highly recommended, and one of the most rewarding in the series.