FrozenPlain tells us that Obelisk is a MIDI plugin instrument that harmonises input MIDI and outputs it to your synths. They say that this VST is designed to be a flexible way of experimenting with chords and harmonies. Obelisk's chord picker allows you to pick what harmonies should be applied to each note. As well as this, Obelisk features an optional constraining algorithm that will ensure the harmonies fit your chosen key and scale.
Features:
Obelisk is currently available as a VST2.
Pricing and Availability:
$25
More information:
Older Music Machines & the People Who Still Use Them