How to Play the Harmonica
There are various methods of playing, depending on the type

When playing the harmonica, take the instrument in your hand, set in front of your mouth, and then blow and draw through the mouthpiece while moving the instrument left and right, vibrating the reeds and producing notes.

How to play chords

With any harmonica, you can produce a note that you want to play by setting the hole for the note in front of your mouth and playing. Chords are played similarly: Typically, you bring all holes required for the chord in front of your mouth and close off the holes that are not needed with your tongue. When you want to insert accompanying notes into the chord, play with your tongue removed from the holes for those notes.
Incidentally, harmonica performances with chords are typically played with double-reed harmonicas or 10-hole harmonicas.

There is a fairly special harmonica, the Yamaha Melo Chord, that offers twice the enjoyment from one instrument.
The Yamaha Melo Chord is constructed with a mouthpiece on either side, one of which is for a single-reed C, D, E, F, G, A, B, C harmonica, whose counterpart is that of a cord harmonica that can easily produce five chords, including C-E-G, F-A-C, and G-B-D. The central portion is partitioned at an angle, and breath comes out of holes in the center, so two people can play with their foreheads touching. If both sides are played, an ensemble can be performed with a single instrument.
Because of the way in which it has been devised, the chord-harmonica side also allows unique performances. In groups of three holes each, the left-most is the low note. Thus, if the player starts by blowing into the left hole and then moves on to blowing into all three holes, he or she can create a thud-cha-cha-cha rhythm.

 

The fusion of a single-reed harmonica and a chord harmonica with sets of three holes each

Rear side of the harmonica.

The harmonica can produce notes reminiscent of a brass instrument or the accordion. This section will explain various methods of playing that produce notes that one would not think were played on a harmonica.

Hand vibrato method

This expressive method adds emotion to the notes played by shaking the instrument with the palm of the hand.

Hand vibrato method "Furusato"

Violin method

Just the top row of a double-reed harmonica is used to play, producing tones that sound like a violin.

Violin method "Aka Tonbo"

Bass method

A method by which a melody can be played while beating a rhythm. All by yourself, play the melody toward your right cheek, while, from the left, strike the mouthpiece with your tongue to block the holes of notes you do not want to sound. Leave the tongue there moving, striking the front of the mouthpiece, and creating a rhythm as you play.

Bass method "Long, Long Ago," an Irish Folk Song

A feature of the chromatic harmonica is that it is able to play chromatic-scale notes, but these can also be played on regular double-reed harmonicas. In this case, two instruments are played, one playing the notes that would be the white keys on a piano, and the other playing the notes for the black keys.
While playing, the harmonicas are raised and lowered, as necessary, with the harmonica being played placed in front and the harmonica not being played lowered toward the back. The mouthpieces become narrower on the oblique. Therefore, four holes are stuck together, which is supposed to be easier to play once one is used to it.

The layout of the notes is such that the lower notes are lined up to the left and the higher notes to the right, but the instrument can also be played turned upside down. Holding the instrument so that the notes get higher the farther to the left you go might be a good mental exercise.