Domenico Cantone Salvatore Cristofaro Simone Faro On Some Combinatorial Problems Concerning the Harmonic Structure of Musical Chord Sequences. 103-124 2008 19 Int. J. Found. Comput. Sci. 1 http://dx.doi.org/10.1142/S0129054108005565 db/journals/ijfcs/ijfcs19.html#CantoneCF08