You can use the following system exclusive messages to turn off or on parts in Roland GS sound sources. You will need to input and send these from a sequencer that allows you to create SysEx messages from scratch.
To Turn a Part Off
Part / Message
1 / F0 41 10 42 12 40 11 02 10 1D F7
2 / F0 41 10 42 12 40 12 02 10 1C F7
3 / F0 41 10 42 12 40 13 02 10 1B F7
4 / F0 41 10 42 12 40 14 02 10 1A F7
5 / F0 41 10 42 12 40 15 02 10 19 F7
6 / F0 41 10 42 12 40 16 02 10 18 F7
7 / F0 41 10 42 12 40 17 02 10 17 F7
8 / F0 41 10 42 12 40 18 02 10 16 F7
9 / F0 41 10 42 12 40 19 02 10 15 F7
10 / F0 41 10 42 12 40 10 02 10 1E F7
11 / F0 41 10 42 12 40 1A 02 10 14 F7
12 / F0 41 10 42 12 40 1B 02 10 13 F7
13 / F0 41 10 42 12 40 1C 02 10 12 F7
14 / F0 41 10 42 12 40 1D 02 10 11 F7
15 / F0 41 10 42 12 40 1E 02 10 10 F7
16 / F0 41 10 42 12 40 1F 02 10 0F F7
To Turn a Part On
Part / Message
1 / F0 41 10 42 12 40 11 02 00 2D F7
2 / F0 41 10 42 12 40 12 02 01 2B F7
3 / F0 41 10 42 12 40 13 02 02 29 F7
4 / F0 41 10 42 12 40 14 02 03 27 F7
5 / F0 41 10 42 12 40 15 02 04 25 F7
6 / F0 41 10 42 12 40 16 02 05 23 F7
7 / F0 41 10 42 12 40 17 02 06 21 F7
8 / F0 41 10 42 12 40 18 02 07 1F F7
9 / F0 41 10 42 12 40 19 02 08 1D F7
10 / F0 41 10 42 12 40 10 02 09 25 F7
11 / F0 41 10 42 12 40 1A 02 0A 1A F7
12 / F0 41 10 42 12 40 1B 02 0B 18 F7
13 / F0 41 10 42 12 40 1C 02 0C 16 F7
14 / F0 41 10 42 12 40 1D 02 0D 14 F7
15 / F0 41 10 42 12 40 1E 02 0E 12 F7
16 / F0 41 10 42 12 40 1F 02 0F 10 F7
To Turn a Part Off
Part / Message
1 / F0 41 10 42 12 40 11 02 10 1D F7
2 / F0 41 10 42 12 40 12 02 10 1C F7
3 / F0 41 10 42 12 40 13 02 10 1B F7
4 / F0 41 10 42 12 40 14 02 10 1A F7
5 / F0 41 10 42 12 40 15 02 10 19 F7
6 / F0 41 10 42 12 40 16 02 10 18 F7
7 / F0 41 10 42 12 40 17 02 10 17 F7
8 / F0 41 10 42 12 40 18 02 10 16 F7
9 / F0 41 10 42 12 40 19 02 10 15 F7
10 / F0 41 10 42 12 40 10 02 10 1E F7
11 / F0 41 10 42 12 40 1A 02 10 14 F7
12 / F0 41 10 42 12 40 1B 02 10 13 F7
13 / F0 41 10 42 12 40 1C 02 10 12 F7
14 / F0 41 10 42 12 40 1D 02 10 11 F7
15 / F0 41 10 42 12 40 1E 02 10 10 F7
16 / F0 41 10 42 12 40 1F 02 10 0F F7
To Turn a Part On
Part / Message
1 / F0 41 10 42 12 40 11 02 00 2D F7
2 / F0 41 10 42 12 40 12 02 01 2B F7
3 / F0 41 10 42 12 40 13 02 02 29 F7
4 / F0 41 10 42 12 40 14 02 03 27 F7
5 / F0 41 10 42 12 40 15 02 04 25 F7
6 / F0 41 10 42 12 40 16 02 05 23 F7
7 / F0 41 10 42 12 40 17 02 06 21 F7
8 / F0 41 10 42 12 40 18 02 07 1F F7
9 / F0 41 10 42 12 40 19 02 08 1D F7
10 / F0 41 10 42 12 40 10 02 09 25 F7
11 / F0 41 10 42 12 40 1A 02 0A 1A F7
12 / F0 41 10 42 12 40 1B 02 0B 18 F7
13 / F0 41 10 42 12 40 1C 02 0C 16 F7
14 / F0 41 10 42 12 40 1D 02 0D 14 F7
15 / F0 41 10 42 12 40 1E 02 0E 12 F7
16 / F0 41 10 42 12 40 1F 02 0F 10 F7