4.26A simple accompaniment setup

Try this:

Left hand:

single root

Right hand:

three-note chord with melody on top

Example:

Chord C, melody G:

LH: C

RH: C E G

Chord Am, melody C:

LH: A

RH: E A C

Chord F, melody A:

LH: F

RH: C F A

Chord G7, melody B:

LH: G

RH: D F B

This is already a very usable piano arranging technique.