The Harmonica, or mouth organ, was invented in the early 1900's and remains one of the world's most popular musical instruments. The many types of harmonica include diatonic, chromatic, tremolo, octave, orchestral, and bass versions. Big Music carries a wide range of harmonicas from top brands including Hohner and Lee Oskar, in all different keys. Let us know if you need help finding the right harmonica for you.