Abstract: A tone generator for electronic musical instruments, useful in particular for the modular composition of an electronic organ, comprising a plurality of inputs corresponding to a keyboard octave of the musical instrument. The inputs are connected to a plurality of groups of analog modulators which receive, respectively, tone signals produced by a tone generator and submultiples thereof produced by a plurality of toggles according to the number of footages desired on the output of the groups of modulators. The tone generator includes an audio frequency modulator having a high modulation index with full modulation depth remaining substantially constant over the whole supply voltage range.