A chord judging apparatus for judging chords of a musical piece, is provided with a processor and a memory for storing data of the musical piece, wherein the processor specifies plural segments in the data of the musical piece, estimates a tonality of each of the specified segments based on component tones included in the segment, and judges a chord of the plural segments of the musical piece based on modulation in tonality, when modulation is introduced in the estimated tonalities of the plural segments.

Digital signal processing and machine learning techniques can be employed in a vocal capture and performance social network to computationally generate vocal pitch tracks from a collection of vocal performances captured against a common temporal baseline such as a backing track or an original performance by a popularizing artist. In this way, crowd-sourced pitch tracks may be generated and distributed for use in subsequent karaoke-style vocal audio captures or other applications. Large numbers of performances of a song can be used to generate a pitch track. Computationally determined pitch trackings from individual audio signal encodings of the crowd-sourced vocal performance set are aggregated and processed as an observation sequence of a trained Hidden Markov Model (HMM) or other statistical model to produce an output pitch track.

A method for following a musical score in real time. At least one sound emitted by a performer is recorded. At least one chromatic vector is estimated. The chromatic vector is compared with theoretical chromatic vectors of the musical score. A transition between the chromatic vector and a previous chromatic vector with theoretical transitions of the musical score is compared. A work position of the performer depending on a previous work position is estimated from the comparison of the chromatic vector and the comparison of the transition. The recording is carried out for a suitable period depending on the ratio between a period of the transition and a reference period.

A method for following a musical score in real time. At least one sound emitted by a performer is recorded. At least one chromatic vector is estimated. The chromatic vector is compared with theoretical chromatic vectors of the musical score. A transition between the chromatic vector and a previous chromatic vector with theoretical transitions of the musical score is compared. A work position of the performer depending on a previous work position is estimated from the comparison of the chromatic vector and the comparison of the transition. The recording is carried out for a suitable period depending on the ratio between a period of the transition and a reference period.