Baritone saxophonist Gerry Mulligan was a potent artist whose reach extended into many different areas of jazz across six decades. As a dominant arranger and player in the 1940s, he influenced big bands led by Gene Krupa, Elliot Lawrence and Claude Thornhill, fusing bop and swing. In 1949 and ’50, he was a member of Miles Davis’s so-called Birth of the Cool band as a player, arranger and composer…