There are three ways to control harmonies and keep them in key with the singer:
Chord mode where the VW watches incoming MIDI and analyzes it to determine what chords are being played, then creates harmonies using only notes from the chord it has recognized. The user can decide the position ofeach the harmony voices being created - above or below the singer. If you don't have MIDI but want the sound of Chord Mode, you can do what our Demonstrator Marc Cooper does and set up a Preset in Song Mode, creating a series of steps in the Song where each Step is a chord preset but with a different root. He uses the Switch-3 to advance through these chords. Notes mode where the VW harmony voices are controlled directly by incoming MIDI notes - what you play is what you get.
Scale mode where the singer tells the VW what key and scale combination fit the song, and chooses the position of each of the voices being created -above or below the singer and how many notes away in the selected scale. Most popular singers harmonize by singing above or below the lead singer and choosing notes that are in the same scale and key as the song, so you will find that Scale Mode will actually be a great choice for most songs.
Most popular songs can be harmonized using only one key/scale combination,so one preset will generally do the job for one song. For example, if you sing 'happy birthday' with your first note as 'G', you are singing it in the key of C Major. In western music, you can typically get great harmonies if you simply choose harmony notes from a set that includes notes an octave lower than you, an octave higher, notes a 'third' and 'fifth' above, and notes a 'fourth' and 'sixth' below you. Always count the note you are on as 'one' when counting up or down to make this work! Note that a note a 'third' above you is an octave higher than a note a 'sixth' below, and that a note a 'fifth' above you is an octave higher than a note a 'fourth' below. So, if you don't have MIDI, Chord Mode (using the Song Mode) or a Scale Mode Preset are the ones to use. With most popular music you won't have to change key or scale, but if you do, you can always use MIDI or, if you don't use MIDI, the footswitch can be used to advance through a sequence of scale presets or chords in Song Mode!