Use the mouse X to control the slide, and move the mouse up and down to control the partials (how high of a note you play at each slide position). The partial levels are marked with lines. Use z to stop and start recording. If you play too fast when you are recording, sometimes the recording doesn't play some of the notes due to lag. Post your best recordings in the comments section!
Sorry for the poor artwork, that was the only image of a trombone that worked for this project that I found.
