Some time ago CodeFN42 released a midi chord effect called 'Cales' and I spoke about it here.

It was quite a good little tool, however, they have now taken it to the next level by releasing a VST plugin called 'Chordz' which is really great. It fixes all the little points which were missing before.

Chordz is a VST plugin that allows you to trigger full chords by playing single notes.

Each trigger note is associated with a separate chord. Each chord may consist of any number of notes. Play complicated chord progressions with one finger, with a MIDI keyboard or a drum-pad, or trigger chords from single notes added in your DAW's piano roll.

You can give a human feel by altering the start point and/or velocity of each note, which can also be randomized to give a very natural sound to the chords.

Chordz comes with more than 40 scale/chord templates, and a chord library with more than 50 chord types. You can add your own custom templates, and new chord types by editing the relevant text file. And you can, of course, customize the chords directly in the GUI.

It's available for Windows XP/Vista/7/8/10. VST2 compatible 32-bit or 64-bit host and can be downloaded FOR FREE at CodeFN42 here.

They explain (really useful point) how to connect in most major DAW's (Ableton is explained here). I placed an Arpeggiator in line with it for some great idea generation.