The Complete Louis Armstrong Decca Sessions (1935-1946) (Mosaic, seven CDs). Most jazz critics regard the late Twenties and early Thirties as Satchmo’s peak years, but a vocal and steadily growing minority begs to differ. This box set will give them plenty of ammunition. Armstrong had simplified and purified his flamboyant style by the time he signed with Decca in 1935, and no apologies of any kind need be made for the recordings he made with his big band and a delightfully wide variety of guest artists, including Sidney Bechet, Bing Crosby and the Mills Brothers. Put on “2:19 Blues,” “Darling Nellie Gray,” “Ev’ntide,” “Jodie Man,” “Jubilee,” “Nobody Knows the Trouble I’ve Seen,” “Struttin’ with Some Barbecue,” or “Wolverine Blues” and you’ll get the point instantly. Many of these 78 sides are comparatively unfamiliar, and all have been digitally remastered to gorgeous effect. Dan Morgenstern’s liner notes deserve a Grammy, or maybe a Nobel Prize. This one’s a must, and then some (TT).