Articulate natural landscape features as sound.
For example, a mountain range suggests changes in volume whilst the meandering course of a river describes the pitch movement of a melody line.
Repeat this process many times.
Then begin to imagine sounds which match what you see in the sky.
Let these play as a silent counterpoint to your humming.
© Bob Dickinson 1997
Text Music home page
http://www.indigogroup.co.uk/txtmusic/