Methods and apparatus to extract a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes an audio characteristic extractor to determine a logarithmic spectrum of an audio signal; transform the logarithmic spectrum of the audio signal into a frequency domain to generate a transform output; determine a magnitude of the transform output; and determine a timbre attribute of the audio signal based on an inverse transform of the magnitude.

Methods and apparatus to extract a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes an audio characteristic extractor to determine a logarithmic spectrum of an audio signal; transform the logarithmic spectrum of the audio signal into a frequency domain to generate a transform output; determine a magnitude of the transform output; and determine a timbre attribute of the audio signal based on an inverse transform of the magnitude.

A method of and system for generating audio having pitch attributes of an incoming audio stream. The method comprises receiving a digital audio input. The audio spectrum is analyzed and integrated over segments of digital audio data upon receiving analysis triggers which can be synced with the audio tempo. The integrated spectrum is processed to find peak frequencies in the spectrum and their associated gain stored in a peaks array. The peak frequencies are used to program the oscillators controllable attributes and characteristics. The synthesis is performed upon receiving an analysis clock. A number of digital oscillators are configured with the associated frequency parameters and gain parameters from a peaks array. The oscillators are configured according to the audio pitch analysis and generate an oscillator output at the frequency and gain specified in the peaks array. These oscillator outputs are summed together generating synthesized audio.

Methods, systems and computer program products are provided for identifying an audio stem. Audio stems (t.sub.1, . . . , t.sub.N) are stored on a stem database and songs (S.sub.1, . . . , S.sub.P) made with at least a subset of the plurality of the audio stems (t.sub.1, . . . , t.sub.N) are stored on a song database. At least partially composed song (S*) having a predetermined number of pre-selected stems (k) are received. In turn, a probability vector (or relevance value or ranking) is produced for each stem (t.sub.1, . . . , t.sub.N) to be complementary to the at least partially composed song (S*).

A method of and system for generating audio having pitch attributes of an incoming audio stream. The method comprises of receiving a digital audio input. The audio data is analyzed upon receiving an analysis trigger indication which can be synced with the audio tempo. The analysis includes a Fast Fourier Transform of a segment of digital audio data.

The integrated spectrum is process to find a number of peak frequencies in the spectrum and their gain. A number of the peak frequencies are used to program a number of oscillators and the parameters determined during analysis and controllable attributes and characteristics of the oscillators. The synthesis is performed upon receiving an analysis clock. First, a number of digital oscillators are configured with the associated frequency parameters and gain parameters from the peaks array; The number of oscillators configured according to the audio pitch analysis and are generated an oscillator output at the frequency and gain specified in the peak array. These oscillator output are summed together thereby generating synthesized audio.

Methods and apparatus to extract a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes an audio characteristic extractor to determine a logarithmic spectrum of an audio signal; transform the logarithmic spectrum of the audio signal into a frequency domain to generate a transform output; determine a magnitude of the transform output; and determine a timbre attribute of the audio signal based on an inverse transform of the magnitude.

Methods, systems and computer program products are provided for identifying an audio stem. Audio stems (t.sub.1, . . . , t.sub.N) are stored on a stem database and songs (S.sub.1, . . . , S.sub.P) made with at least a subset of the plurality of the audio stems (t.sub.1, . . . , t.sub.N) are stored on a song database. At least partially composed song (S*) having a predetermined number of pre-selected stems (k) are received. In turn, a probability vector (or relevance value or ranking) is produced for each stem (t.sub.1, . . . , t.sub.N) to be complementary to the at least partially composed song (S*).

Methods and apparatus to classify media based on a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes means for accessing a media signal; and means for: determining a spectrum of audio corresponding to the media signal; and determining a timbre-independent pitch attribute of audio of the media signal based on an inverse transform of a complex argument of a transform of the spectrum.

Methods and apparatus to classify media based on a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes means for accessing a media signal; and means for: determining a spectrum of audio corresponding to the media signal; and determining a timbre-independent pitch attribute of audio of the media signal based on an inverse transform of a complex argument of a transform of the spectrum.

Methods and apparatus to classify media based on a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes an interface to access a media signal; and an audio characteristic extractor to determine a spectrum of audio corresponding to the media signal; and determine a timbre-independent pitch attribute of the audio based on an inverse transform of a complex argument of a transform of the spectrum.