An alignment based system for chord sequence retrieval

Music retrieval systems for Western tonal music digital li-braries have to consider rhythmic, timbral, melodic and har-monic information. Most existing retrieval systems only take into account melodies. Melody comparison may induce er-rors since two musical pieces can be very similar whereas their melodies may differ in a significant way. In this paper, we propose to investigate and experiment a retrieval system based on the comparison of chord progressions. The defini-tion of chords may be ambiguous but their properties can be precisely described and represented. We detail the adap-tations of alignment algorithms, successfully applied for the estimation of symbolic melodic similarity, for chord progres-sion retrieval. Several experiments, performed on symbolic databases, show that the system described is robust to vari-ations and outperforms a recent chord retrieval system