Chromatic Harmonicas are designed to play every complete scale in any key - major, minor, pentatonic, blues, etc. - all on one instrument. Additionally, all accidental notes are available at any time for any situation. Each single hole contains four reeds: two natural notes and two chromatic notes are enabled by pushing a slide button on the side of the harmonica. Most chromatics are solo tuned, meaning each group of four single holes covers a complete octave. This design offers a wealth of new musical options to the player. Most often, chromatic harmonicas are heard within the classical and jazz scenes, but they are frequently found in blues, folk, rock and pop music.