Lee Oskar Major Diatonic Harmonica A Flat At Guitar Paradise we have a great range of Harmonicas, available both instore and online through our webstore! The Major Diatonic Harmonica was originally intended for playing simple Folk music of the nineteenth century and its notation layout was adequate for that purpose. The Major Diatonic harmonica is the most commonly used tuning for playing Blues, Rock, Country Folk and Jazz. Several other manufacturers, using various names stamped on their cover plates, for marketing purposes, have the exact same notation layout as a Lee Oskar Major Diatonic harmonica. Features Traditional blues (major diatonic) tuning Suits Blues, Rock, Country, Folk, and Jazz Key of A Flat Image is for illustrative purposes only.