The Trautonium and the Hammond Novachord (among others) used frequency dividers to create multiple pitches from one signal. In this patch, one lonely sine wave creates 3 pitches using 3 frequency dividers (we’re using Count Modula’s Voltage Controlled Frequency Divider MkII).

On the Frequency Divider , just above the “IN” cable is a knob. It has 1 to the left and 21 to the right. turning the knob all the way to the left doubles the current note at the same pitch. If you start turning the knob to the right you’ll start to hear it divide the pitch down.
I think some synths in the 70s and 80s used this method also. It was cheaper.

The Zip file has 3 files. The FREQ-DIVIDE PLUCK CV-MOD patch has the LFO controlling the frequency settings. The other 2 patches don’t.