The ProKeys Sono keyboard has a full General MIDI (GM) sound set with 128 sounds built-in. The built-in GM sounds can be accessed in two ways:
 

Method 1: Recall a specific General MIDI instrument in Edit mode

Appendix A in the ProKeys Sono user guide lists the built-in General MIDI instruments by their sound numbers. Access a specific instrument by entering its number in Edit mode:

1. Press the Edit Mode button.
2. Press the black key above F5 (F#5) on Sono 61, or press the black key above F6 (F#6) on Sono 88, representing “Program.”
3. Enter the desired program number, using the white keys between G4 and B5 on Sono 61, or the white keys between G5 and B6 on Sono 88.
4. Press C6 (Enter) for Sono 61, or C7 for Sono 88, to confirm the selection.

Method 2: Browse General MIDI instruments using the Data buttons

Reassigning the Data buttons to send program change messages will allow you to step through and audition the built-in
General MIDI sounds in consecutive order. To configure the Data < > buttons to send program change messages:

1. Press the Edit Mode button.
2. Press the black key above F2 (F#2). (ProKeys Sono will automatically exit Edit mode).
3. Press the Data > and < buttons to step forward and backwards through the built-in GM sounds.

To return the Data keys to control the octave shift value:

1. Press the Edit Mode button.
2. Press the black key above C2 (C#2) on Sono 61, or the black key above D3 (D#3) on Sono 88, representing “Data = Octave.” (ProKeys Sono will automatically exit Edit mode).