Oct 15 2008
Guide to playing guitar with a harmonica
Whether you want to use a harmonica stand and be a one man band or you want to jam along with a friend who plays the harmonica, it is good to know how the two instruments interact with one another. The harmonica is in a key. A C harmonica has a scale that can be harmonized to songs whose’ respective keys falls within the C scale.
Typically it is easiest to remember it this way; If you are playing a song in the key of G on a guitar, your harmonica accompaniment should be played on a harmonica in the key of C. From there it is all simple mathematics. Play along to an A note harmonica in the key of E and so on and so forth. To find what key you should be playing in for a harmonica, simply find the note of the harp on the guitar string, then find the note on the next string above, directly on top of it. (i.e. The E note appears directly over top of the A note, The G on top of C ect.)
Here is a simple chart you can refer to when you need to decide which key of harmonica is appropriate to play along to a song in a certain key.
Harmonica key: A - B - C - D - E - F - G
Guitar Key:E - F - G - A - B - C - D
Well, you almost got it right. But the “next string up” theory isn’t quite accurate. When playing harp in the (most used) blues “cross” style, (known as 2nd position on harp), which you’re apparently referring to , the Circle of 5ths is the best “chart” to use. The harp is 4 steps up from the guitar key. If the song is in ‘E’, count the E as 1, F as 2, G as 3, A as 4. You play the A harp. So key of E on guitar gives you the A harp, as you mentioned. However, Key of F on guitar brings you to a Bb harp, not a B.
My apologies, I figured people would guess the flats. I was referring to the notes stamped onto the harps. I didn’t realize there were both B and Bb harps, I thought people would assume I meant the flats. I may have to correct this one.