The technique essential to playing harmonica is knowing how to play one note at a time. When a person can play each note distinctly, he or she can then play beautiful solo melodies. One of the main techniques for playing straight harmonica is the Tongue Blocking method. This allows the player to add accompaniment to his melody by making chords by lifting the tongue off the covered notes. One of the main techniques for playing Blues harp is bending notes and having control over the strength of the bend, thus being able to have control over the pitch of the note.
Some notes have to be bent a half step, and some notes have to be bent a whole step.
Harmonicas have'nt changed much over the past one hundred years. The prices have, though. I remember my Father and my Uncles saying a Marine Band Harmonica used to cost fifty cents when they were growing up. When the Hohner Blues Harp was released, I started playing that model as my main Harmonica. Then Hohner issued the Special 2O Harmonica.