A line, in stereo
The note never moves; its place does. A second line steers the pan:
pan: 1 9 1 # 1 = full left, 9 = full right, 5 = center
Read over the length of the clip, those three points become a smooth sweep — hard left, across to hard right, and back — interpolated sample by sample. Pan is just a value paired with time, the same projection that moves the scale or the key under a fixed phrase. Here it moves the space.