Hello Abacus.

To answer your questions:

1. Chops is a slang term for good skills.

2. Half pedalling, is basically a way of emulating a real sustain pedal, on a real piano. Since the sustain pedal on a real piano is mechanical, you can hear the effect of it by just pressing it slightly down, and you can hold a note and press it up and down and you can hear it. On a digital piano you can't do this. So they made half pedalling, which is basically two different points in the pedal, triggering two different samples.

3. Rootles Chord Recognition is a jazz thing. For jazz players, who play in ensembles with a bass player, the piano player usually stay away from playing the root note of the chord. For solo players, they often play single roots, then answer with a rootless chord in the left. A rootless chord will have the root, and also in some cases other notes of the chord are omitted. Example: Cmaj9 is usually voiced C E G B D, but one rootless version would be E G B D, or it can be G B D E, or B D E G. A regular arranger would translate those chords into: Em7 or G6. Which will sound wrong. Rootless Chord Recognition, recognises those chords as Cmaj9.

Cheers!

Doc-Z