On my Korg I use Songbook but most of the time I replace the default factory voices with my preferred voices for each song. With the Genos and 10 registration buttons the options are unlimited but for the most part I use buttons 1, 2, 3 and 4 for different voices and/or variations. Buttons 8 to turn on vocal harmony 9 to turn it off button 10 for an ending. Buttons 5, 6 and 7 I sometimes use to change voices but not always.