"Hi, my name is Marcus Milius. I play harmonica. I got a degree at the University of Southern California, a Bachelor's of Music, in Jazz Studies - Chromatic Harmonica. I play and teach harmonica here in New York City, and I'm happy to show you what I do.
Alright, so playing the chromatic harmonica, you'll first need a chromatic harmonica, rather than a diatonic harmonica. The technique is pretty basic. Once you get a single note on a diatonic, the same technique applies to the chromatic. The only difference is, you have a slide on the chromatic harmonica, to get you the notes that you ordinarily bend or over-blow to on the diatonic. That makes it a lot easier to hit notes that aren't in the key, you simply press the button and it sharps any note up a half step. So, if you have a C, it sharps up to a C sharp, D, up to a D sharp. So all notes will sharp up a half step when you press the slide. The thing that does make that difficult is playing in C is very easy but playing in other keys means you have to locate the correct notes and know when not to press in the slide and when to press in the slide. So, each scale, each key is very different. So, here would be a major sound in several keys. So, each key is a different pattern that you have to learn. You can do some bending on the chromatic, it doesn't sound quite as bluesy as when you do it on the diatonic."