Ethan Iverson, best known as a founding member of the pomo trio the Bad Plus, is not only one hell of a pianist but one of the most lucid, thoughtful, and studious jazz writers on the planet. He has a knack for making egghead obsession and technical analysis clear, interesting, enlightening, even entertaining. Through his excellent blog, Do the Math, he’s offered in-depth interviews with some of jazz’s most important living practitioners as well as probing essays that get to the heart of some of the music’s most dynamic artists. Iverson is a fan, but he’s not blinded by ardor, and that’s something you can see in his critical commentary on the brilliant pianist Lennie Tristano, where he disputes some of the negative generalizations the innovator made in vintage interviews. But Iverson clearly loves Tristano‘s music and the work of his two key disciples, saxophonists Warne Marsh and Lee Konitz. In fact, he’s both played with the latter and interviewed him several times. Costumes Are Mandatory (HighNote), a fantastic new album due out Tuesday, builds on their relationship.