The FunkyTown Generator is a FunctionGenerator that takes an audio signal as its trigger.
The idea behind it is to create a TimeIndex that is triggered when an audio signal (in this case labeled "LFO") becomes positive. It is subtracted from itself delayed by one sample to create a one-sample trigger. A Sign Sound (labeled here as “Positive Zero or Negative’) resets the timeIndex to -1 if its input is positive. At all other times it outputs the previous value of the timeIndex plus a small increment (called “SISound”).
In this example, the timeIndex is used as the index into a SampleWithTimeIndex. This gives you independent controls over the rate of retriggering (the frequency of the 'LFO' in this case) and the rate (the size of the 'SI Sound' in this case).
In the file, there is also an example of using the Funky Town Generator to do hard sync (where one oscillator resets the phase of another one, using the OscillatorWithTimeIndex).