HPCP is a vamp plug-in for audio feature extraction that computes the instantaneous evolution of HPCP (Harmonic Pitch Class Profile) of a signal. 

The HPCP is an approach for chroma feature estimation which represents the pitch content of polyphonic music signals, mapped to a single octave. HPCP have been extensively used for several final applications such as key and chord estimation, similarity computation (cover version identification) and music classification.

Full details of the algorithm can be found in the following papers:

NOTE: The main difference between this implementation and the original algorithm is that this implementation does not perform automatic tuning frequency estimation. The reference tuning frequency is defined as an input parameter.

We would highly appreciate if scientific publications of works partly based on the HPCP plug-in cite the above publications. 

HPCP vamp plug-in has been made possible by the kind support of the entities mentioned in the acknowledgements.