The Major Diatonic harmonica is the most commonly used tuning for playing Blues, Rock, Country, Folk & Jazz. The main Diatonic harps are produced by several manufacturers using different names such as Blues Harp, Marine Band, Golden Melody, Big River, Special 20, Pro Harp, Folk Master, Star Performer, etc. Although the cover plates are marked with a variety of different names for marketing purposes, all of these harmonicas have the same note layout as the Lee Oskar Major Diatonic. The most important difference concerns the quality of materials, construction, design, and sound.