method for modelling time variant signals and multiple tone generating apparatus for a real time controllable time variant waveform synthesizer speech or musical tone generation is accomplished by storing a dsq codebook representation of a time variant signal a dsq codebook is a parametric representation of a time variant signal wherein a signal 39 s parameters are a time variant amplitude data sequence a time variant pitch data sequence and a data sequence corresponding to a set of invariant waveshapes and their corresponding duration values a signal is reconstructed by concatenating periodic segments of finite duration and scaling its amplitude via a time variant amplitude data sequence and altering pitch or harmonic content via a time variant pitch data sequence a plurality of unique dsq codebooks and tone generators are assigned to a plurality of key actuations for multi timbral operation application_number US 99147292 A description referring now to the several figures in which like reference numberals depict like items and initially to fig1 there is shown a schematic block diagram of a real time programmable time variant waveform synthesizer in accordance witht he invention the synthesizer employs a method of demodulated segment quantization dsq the principles of which are discussed below generally the discussion showns that the amplitude envvelope and pitch variance can be separated from a digitized time variant waveform the amplitude and pitch information can then be demodualted to provide a signal having both a constant amplitude and constant pitch this signal is of a much smaller spectral density than the complete time variant signal and can thus be processed and encoded in real tiem usign a relatively.