Once again this year, I'm cutting to the chase, but an introductory article as well as the winners list below can be found here. From that article:
With 28,496 voters casting ballots, the 2015 poll generated the largest voter turnout in the history of the DownBeat Readers Poll. . . .
The December issue of DownBeat contains the complete results in all 34 Readers Poll categories, highlighting more than 650 artists. The poll results include 90 of the year’s top albums in Jazz, Blues and Beyond.