Chord recognition using Doubly Nested Circle of Fifths

This paper presents a chord recognition method from music signals using chroma vectors and musical knowledge known as "Doubly Nested Circle of Fifths (DNCOF)". DNCOF represents the relationships of major and minor chords where the neighboring two triads are similar. We obtain a novel feature from chroma vectors by mapping them onto two-dimensional DNCOF coordinate, which we call "DNCOF vectors". We expect that the DNCOF vectors can contribute to correcting false recognition obtained by the chroma vectors when their mapped positions are apart from one another in the DNCOF coordinate. In this research, we evaluated our proposal using the Beatles' datasets and showed its effectiveness.