Chummy Macgregor was more important as a friend and longtime associate of Glenn Miller than he was as a member of Miller's band. He and Miller first met as members of Smith Ballew's band, which Miller joined in 1932 as a trombonist. Macgregor came in on piano a little later, and the two developed a friendship that endured for more than a decade. Macgregor was only a fair pianist and a not-very-inspired arranger, but he was, according to author George T. Simon in his biography of Miller, a dedicated member of the band and a loyal friend to Miller. Indeed, most Miller fans and movie buffs in the 21st century probably know MacGregor best for his screen incarnation, in the guise of actor Harry Morgan, in The Glenn Miller Story, in which he is depicted as a close partner to Miller from his earliest days. In reality, he was a marginal musical presence, whose dragging tempos drove various members of the band to distraction, and whose main virtues were personal; in fairness, he can be heard on literally hundreds of sides, . Almost fittingly, MacGregor was never able to extend his professional career past the point of Miller's death in late 1944. He was a consultant on The Glenn Miller Story starring James Stewart, however, which seems to have been a major reason for the prominence of his character in the first half of the movie.