On your device, click the ‘Vocal FX’ button, then hold any of the buttons which are lit up. This will open the Advanced Harmony menu, where you can edit the scale which the harmony voices sing in, the portamento level and the humanize level. 

The choice of scales is as follows: Maj1, Maj2, Maj3, Min1, Min2 or Min3. You can see in the table below how each of these choices translates into the notes which the device will choose to use to harmonise with your voice. If the device does not allow you to change this parameter, you may have the Harmony Key set to ‘Auto.’ You’ll need to go back to the main Harmony tab and change this if this is the case.

The Portamento level can be set between 0 and 100. The lower this level, the less smooth the transition between notes will be. Similarly, the Humanize level can be set from 0 to 100. Higher Humanize levels will give a less perfect, more ‘real’ sound to your Harmony voices, making it sound more like you have real backing singers on stage with you.