[sdiy] Drone Oscillators

[Spencer Johnson]

Hey, just reposting this for the new list!

I'm building a keyboard based on a Mostek Top Octave divider, and
before the mixer and effects chain i'd like to have some drone
oscillators for harmony, but i don't know what type of circuit i
should use. i'd like to have simultaneous square, sine, and triangle
waves, preferable all independently tunable with coarse and fine
tuning. i've got some designs for a few function generators but i
don't think that the tuning is linear, and that the high ranges would
all be jammed together. should i use a linear vco? any input would be
much appreciated!

-spencer