There are basically two types of Harmonica, the diatonic and the chromatic. The diatonic (commonly known as the blues harp) has a repeated scale in one key eg. a 'C' harmonica will mostly be used with songs in the key of C. Because of this the diatonic harmonica comes in several keys (listed below). The chromatic harmonica has the full scale of notes and can therefore be played in any key, however they do come in different keys for the purpose of prefered hole arrangments for chords. A chromatic harmonica has a slide button on the right hand side which when pressed changes the notes to the sharp '#' notes, giving it the full musical scale. Both types of harmonica have a blow in and draw back note for each hole (see below for charts)

The notes played on a diatonic harmonica can actually be bent with pressure and technique to make other notes, this is done by advanced players to expand the scale on their harmonicas, but it's also common for all players use this technique to a degree and to experiment with sounds. Different mouth positions, voice box and breathing can alter the tone and pitch of a harmonica.

As with the diatonic harmonica, tone and pitch variations can be achieved on a chromatic harmonica with practice.

1. Like any wind instrument, a harmonica needs to be kept free of moisture after     playing. Tap the harmonica hole side down after playing to clear out eccess moisture.

2. Only drink water while playing, never eat while or just before playing.

3. Every few months it's a good idea to take apart the harmonica and clean it out with a     toothbrush dipped in warm water. Pat dry with a cloth afterwards. Be careful not to     disturb the reeds, if you are not confident get a professional to do it for you.