The essential fact, to my mind, is that jazz is an improvised medium. How and in what fashion that improvisation takes place is not germane to the argument, but it is improvised - that's what makes the music "jazz".

Whiteman's orchestra included some of the most talented singers and jazz musicians of the day - mainly white - but what the orchestra played as an entity was not improvised and was not jazz. The scores were carefully orchestrated - and there were some passages - particularly for instrumentalists like Bix Beiderbecke - where some improvised solo passages could be played. But the "King of Jazz" sobriquet was applied to Whiteman by himself. The jazz musicians in the orchestra - Beiderbecke, Frankie Trumbauer, Joe Venuti, Eddie Lang - played their best jazz outside the umbrella of the Whiteman orchestra. The vocalists in Whiteman's male trio "The Rhythm Boys" were Al Rinker, Harry Barris and Bing Crosby and, to some extent, they were able to scat within the confines of the song - "Mississippi Mud" is an example.

Cornettist Dick Sudhalter re-created the Whiteman sound, from the original scores, in two London concerts around 1972. They were fantastic concerts, and the huge sound that emanated from the orchestra showed how little the 78rpm recordings of the time convey the impact of the band. But it wasn't jazz = it was close to it, but not it.

Ellington - the supreme gentleman - was being kind about Whiteman, but the title was nearer to him than Whiteman.

For a better picture of how orchestrated passages could be interspersed with wonderful jazz solos, take any recording of Jelly Roll Morton and the Red Hot Peppers. The contrasting stories of Whiteman - feted to the skies - and Morton - ripped off by the (white) Melrose Brothers - makes sad reading.