The major 7th is an important note in modern music. If you sing or hum any recognizable melody, you will undoubtedly pass the major 7th which is the last note in the major scale. It is 1/2 step below the root note.
When we play a harmonica that is in the key of (C) and we are playing in cross harp/2nd position, the 7th note of the scale would fall on the 5 draw. This note on a (C) harp is an F, but in 2nd position key of (G), we need that note to be an F#. Harmonica players for years have struggled with this situation. Although the note is not absolutely necessary in many blues progressions, it is crucial in jazz, country, popular music, and bluegrass. We can find this note on hole 2 draw bent 1/2 step and can also get the pitch on the upper end on hole 9 and a 1/2 step blow bend. However, most want to be able to get the note in the middle octave, as well.
The use of an over blow on hole 5 will get us the major 7th. The 5 over blow can be a difficult note to hit, especially on a fast passage. So some players have opted for country tuning which raises the pitch of the 5 draw reed 1/2 step. The half-valved harmonica is another option and allows the player to hit the major 7th pitch as a blow bend on hole 6. Watch the video below for a demonstration of these options. At 16:23 Custom Harmonicas, we enjoy working with players to help them become the best they can be. Sometimes this involves working through their musical challenges. Contact me if I can help you. I sell all Seydel diatonic and chromatic harmonicas and am able to modify your Seydel harmonicas for your playing preference. firstname.lastname@example.org