Specifically, generating more than one non-phase synchronized tone could result in a different sound being created on successive key depressions. This distortion is the result of random phase relationships associated with the combined signals, where some harmonics of the signals may add while others cancel. Each channel usually handles multiple waveforms for reasons of economy, since providing a dedicated audio channel for each tone can be very costly.It is well known in the art of electronic tone generation that generating two or more simultaneous notes in a single audio channel, where the tones have pitches that are the same or very close to the same but whose phases are not synchronized, will result in tone color distortion. Thus, electronic organs have been developed as a substitute which is more readily available.Electronic musical instruments usually contain a limited number of audio channels through which tonal information can be processed. Generally, true pipe organs are out of reach of the public because of their substantial expense and size.

The term 'key' includes depressible levers, actuable on-off switches, touch- or proximity-responsive (e.g, capacitance- or inductance-operated) devices, closeable apertures (e.g., a hole in a 'keyboard' of holes which, when covered, closes or opens a fluidic circuit to produce a tonal response), and so forth.The function of an electronic organ is to faithfully reproduce, or simulate by electronic means, the sounds or tones developed by a true pipe organ in response to playing of the organ by the organist a selection of notes, and voices and other characteristics of those notes. The principles of the present invention are, in fact, applicable to any musical instrument in which musical sounds are generated in response to the actuation of key switches regardless of whether those switches are actuated directly, i.e., by the musician's fingers, or indirectly, e.g., by the plucking of strings. The term 'organ' is used throughout the specification to include any electronic musical instrument having a keyboard, such as electronic organs, electric pianos, and accordions. More specifically, the present invention is related to generating digital tones for electronic musical instruments which are phase synchronized.BACKGROUND OF THE INVENTIONThe present invention is particularly adaptable for use in electronic organs. The initializing parameters are transferred from each established oscillator to an associated tone engine for generating the tone whereafter the initiating parameters are transferred from each established oscillator to the associated tone engine.įIELD OF THE INVENTIONThe present invention is directed generally to the generation of tones in electronic musical instruments. Upon determining the rank associated with the selected note, establishing an oscillator for each such determined rank wherein the oscillator includes initializing parameters and initiating parameters for defining a tone of the selected note and the associated rank. The method of the present invention includes receiving a signal representative of a selected note and monitoring a set of available ranks to determine which of the available ranks are associated with the selected note. The tone engines are coupled to each oscillator wherein the initializing parameters are transferred from each oscillator to an associated one of the plurality of tone engines and then the initiating parameters are simultaneously transferred from each oscillator to the associated tone engine. The apparatus also includes a plurality of tone engines for generating tones.

The apparatus further includes an oscillator which is established for each rank determined to be associated with the selected note such that each oscillator includes initializing parameters and initiating parameters which define the selected note and the associated rank. The apparatus includes a microprocessor having an input for receiving a signal representative of a selected note whereupon receipt of the signal, the microprocessor checks a set of available ranks to determine which of the available ranks is associated with the selected note. The present invention provides an apparatus and method for phase synchronizing tones in an electronic musical instrument.

Synchronized tonegenerator