The autoharp and chord zither are two quite different instruments.

The autoharp has a couple of (generally chromatic) octaves of strings which are selected by holding down one of several padded bars to select which strings will be damped, and which will be playable.

The Chord zither has either:

1. Melody strings as above plus several pretuned chords of say 4,5 or 6 strings each. So the melody is played with one hand, and the chords with the other.

OR:

2. Just several pretuned chords of say 4,5 or 6 strings each, but no melody strings.

There is a photo of a chord zither with melody strings at: http://Bardofavalon.ifrance.com/Bardofavalon/musician/Instruments.html . The chords are on the left, melody strings on the right.

Jenny