The Harmony Director lets a band director demonstrate to students how individual notes fit into complete chords, and allows the ability to teach through example rather than words alone - the kind of harmonic understanding that takes many years of experience to develop. The Harmony Director can help an ensemble move from good to outstanding. The Yamaha HD200A Harmony Director was introduced in 2007, and since then has been utilised by band directors worldwide. By listening to feedback from these band directors, the HD300 was developed, with improved usability and extended features for even more productive and efficient rehearsals.