Noun
contrafact (plural contrafacts)
A new musical composition built out of an already existing one, most often a new melody overlaid on a familiar harmonic structure. An important part of the development of bebop. Contrafacts are not to be confused with musical quotations, which borrow rhythms or melodies from an existing composition.
Chord progressions for bebop tunes were often taken directly from popular swing-era songs and reused with a new and more complex melody, forming new compositions (see contrafact ). Source: Internet
Music Parker's style of composition involved interpolation of original melodies over existing jazz forms and standards, a practice known as contrafact and still common in jazz today. Source: Internet