Aah, the mysterious Mangelsdorff! He grew up in Frankfort, Germany, soon mastering guitar and violin but it was on trombone where he made his mark. Since the Nazis banned jazz, he played "patriotic" music at first. In the 1950s, he finally flowered into one of the most unique 'bone men due to his furthering and refining of multiphonics. This meant playing the equivalent of chords and/overtone effects on an instrument that heretofore could only be blown one note at a time. Ornette Coleman, of course, took it one step further and called it harmolodics. Mangelsdorff would literally sing into his trombone which created a secondary note atop or below the note he'd play. Therefore, he could harmonize with himself. The effect was almost psychedelic.
