When on, this holds (ie, sustains) notes that are playing, even if the musician releases the notes. (ie, The Note Off effect is postponed until the musician switches the Hold Pedal off). If a MultiTimbral device, then each Part usually has its own Hold Pedal setting.
Note: When on, this also postpones any All Notes Off controller message on the same channel.
0 (to 63) is off. 127 (to 64) is on.