Abstract: Real-time pitch detection of voiced musical notes involves converting sound waves, produced by a voiced rendition of one or more musical notes, to a time domain electronic audio signal. The electronic audio signal is processed to determine a true pitch of the time domain electronic audio signal. True pitch information is displayed in real-time, concurrent with the voiced rendition of each musical note. A pitch indicator conveys to a user information concerning the true pitch which has been determined. The true pitch is determined by segmenting the electronic audio signal into a plurality of audio signal samples and applying a constant-Q transform. Additional processing steps are applied to reduce pitch detection errors.

Abstract: Collaboratively creating musical harmonies includes receiving a user selection of a particular harmony. In response to this selection, there is displayed on a display screen of a computing device a plurality of musical note indicators or notes to specify a first harmony part of a musical piece to be performed. Real-time pitch detection is used to determine a pitch of each note which is voiced by a person, and a graphic indication of the actual pitch which is sung is displayed in conjunction with the musical note indicators.

Abstract: Method for transcription of voiced musical note includes segmenting an electronic audio signal into a plurality of musical note segments, and sampling each note segment to obtain a plurality of audio samples. For each audio sample, an autocorrelation is computed to determine a probability value associated with certain audio frequencies contained within the audio sample. Local maxima are identified in the energy associated with one or more audio frequencies comprising each audio sample and a corrective function applied to reduce the occurrence of octave errors. A true pitch of each note segment is then determined by converting the pitch identification problem to one involving a shortest path through a graph or network of node. Edge weights are computed for a plurality of adjacent nodes i, j comprising the graph, where each node represents one of the musical note segments.