[Custom(2)] options are displayed when you select [Custom(2)] from the [Select Group ] combo box in the [Instrument] dialog box. You will see the selected instrument in the [ Instrument ] window.

Acoustic Variation Selects the sound of acoustic variation automatically. Undef Variation 1 Selects the sound of undefined variation automatically. Undef Variation 2 Selects the sound of undefined variation automatically. Undef Variation 3 Selects the sound of undefined variation automatically. Undef Variation 4 Selects the sound of undefined variation automatically. Undef Variation 5 Selects the sound of undefined variation automatically. Undef Variation 6 Selects the sound of undefined variation automatically. Undef Variation 7 Selects the sound of undefined variation automatically.