Cross Harp is a common expression used to describe the way the diatonic Richter harmonica (blues harp) is most often played in a blues context. It means that instead of playing the harp in the major key to which it’s tuned, where the blow chord provides the tonal center, you take the draw chord as your starting point. This way of playing is also often referred to as “2nd Position”.
The diatonic harp is usually tuned so that all natural notes belong to the major scale of the key designated on the instrument. The complete scale is found in channels 4 - 7 (see below). On a C harp, this tonal layout produces a C major chord when exhaling (the tonic chord) and a G7 chord when inhaling (the dominant 7th chord).
C major = C E G C
G7 = G B D F
This type of harp was originally intended for folk melodies and the notes of the major scale, in combination with the two chords, allow the player to perform many well known songs in major keys. This style is known as “1st Position” or “Straight Harp”.
In “Cross Harp” or 2nd Position we play in the key of the draw chord, here G7, rather than the key of the blow chord ©. This automatically sounds more bluesy and less major, as the minor 7th F in 5-draw is a “blue note” in the key of G. To play Cross Harp in tune with other instruments, you need to choose a harp key which is 4 scale degrees higher than the key the song is in (for example an A harp to play in E, or a D harp to play in A, see chart). As you can see from the chart, it’s possible to play on any harp in a range of keys derived from the major scale to which it’s tuned.
(Illustrations are from The Harp Handbook, Steve Baker, published by Hal Leonard Group)
The tonal layout also allows the player to modulate the pitch of many of the notes of the draw chord in 2nd Position or Cross Harp (“Bending”) to produce other blue notes such as the flat 5th Db and the minor 3rd Bb. We’ll take a look at this in a future post.
To be continued…