Presumably everyone knows that Louis Armstrong's greatest and most important work was done in the '20s with and around the time of the incredible Hot Five and Hot Seven sessions. During the Swing Era he led a big band and after the war returned to the small group format for the most of the rest of his career with his All-Star bands.

Somehow, by the mid '50s, the idea had taken hold that Armstrong's Swing Era stuff was second-rate, a notion that has persisted until the present day, despite the efforts of writers like Dan Morgenstern to put things in their proper perspective. Now Mosaic Records has taken up the cause with their latest box set, The Complete Louis Armstrong Decca Sessions (1935-46) and have done their usual superlative work. The remastering allows us to hear the music better than we ever could before and Morgenstern has been given the job of writing the liners, which he has done with aplomb and obvious relish. So well does he express his views that it sometimes requires effort for this writer to remember that he doesn't always quite agree ("wait a minute, I don't think Lillie Delk Christian was all that bad" being a typically trivial example).

One of the first points to be made about the music here is that many important musicians of the generation that followed Armstrong have named solos from this period as personal favorites. To some extent this may have to do with which things they heard first, but there is no denying that there are many absolute jewels, from the celebrated remake of "Struttin' with Some Barbecue" to the triumphant version of Jelly Roll Morton's "The Wolverines" or the unforgettable "Swing That Music." He also reaches heights nearly as lofty on a score of other songs that aren't as obviously arranged to build towards a climactic solo. In fact, as far as Armstrong's trumpet playing is concerned, the news is all good. His sound is so richly beautiful and phrasing so breathtakingly perfect, it's no wonder the connoisseurs have always held this vintage in such high esteem. There's scarcely a track that doesn't include at least one memorable turn of phrase. He is also in great form as a vocalist, turning in definitive versions of several classics and working alchemical wonders to turn banal material into gold.

To be sure, not even Morgenstern can pretend that there isn't a fair amount of dross here and there are a couple of other things that potential buyers need to know before taking the plunge. One is, even if we agree that some of Armstrong's greatest playing and singing is featured, that doesn't mean ipso facto that it's the equal of his best earlier work; even if a mere mortal had played cornet on the Hot Fives and Sevens sides, they'd still be highly regarded because of the contributions of Johnny Dodds and Earl Hines and even more for the wonderful group interplay. By contrast, the big bands Louis fronted were usually designed only to show off the leader's abilities, with limited solo space allotted to sidemen. The arrangements were frequently uninteresting and not always played well (especially during the earlier sessions) and a few of the songs were beyond redemption, even by Armstrong.

There were also a number of sessions that presented our protagonist with other popular performers of the day (Bing Crosby and the Mills Brothers among them) with decidedly mixed results. Of greater interest are the smaller group sessions of 1940, especially the reunion with Sidney Bechet, with whom Armstrong had played in 1923. It's a real pity that these two Crescent City masters didn't team up much more often; unfortunately it seems Bechet had issues with Armstrong's greater success.

Many of the things that jazz diehards would count as failings were the very things that helped Armstrong break through with the general public and in that regard we should note that a real appreciation of Armstrong's art at this time has to take into account his effectiveness as a pop performer, apart from his greatness as a jazz artist. Viewed that way, we can understand why some fans have been dismissive, while more discerning listeners have always considered this a period of great fertility.

Tracks: CD1: I'm In The Mood For Love; You Are My Lucky Star; La Cucaracha; Got A Bran' New Suit; I've Got My Fingers Crossed; Old Man Mose; I'm Shooting High; Was I To Blame For Falling In Love With You; Red Sails In The Sunset; On Treasure Island; Thanks A Million; Shoe Shine Boy; Solitude; I Hope Gabriel Likes My Music; The Music Goes 'Round And Around; Rhythm Saved The World; Got A Bran' New Suit (alt tk.-A); I've Got My Fingers Crossed (alt tk.-A); Old Man Mose (alt tk.-A); Old Man Mose (alt tk.-D); Thanks A Million (alt tk.-B); Solitude (alt tk.-C); Solitude (alt tk.-B); I Hope Gabriel Likes My Music (alt tk.-C); Rhythm Saved The World.