Chord harmonica with 8 chords built similar to a ten hole diatonic.

In holes 1-4 blow you will find F-major, 1-5 blow is Fdom7. Holes 1-4 draw is C-Major, 1-5 draw gives Cdom7. In holes 6-9 blow there is G-major, 6-10 blow Gdom7. Holes  6-9 draw is D-major, 6-10 draw gives Ddom7. 

Both chord-blocks (1-5 and 6-10) are separated by a spacer. Therefore the Tonic, the Subdominant and Dominant chords are available for playing in C- and G-major, which makes the instrument very versatile and the perfect choice for playing chord accompaniment. Additionally, the harmonica can be played with single notes (diatonically) to allow 'bass notes interspersed with chordal rhythms'!  

Dr. John Schaman MD and SEYDEL developed this instrument for medical purposes mainly for improving lung function in many respiratory diseases and to reduce the 'normal aging effect of the lungs' ( >H.E.L.P. - Harmonica Exercises for Lung Program), but the "Medical Harmonica" is useful for everyone who wants to accompany songs with this very versatile chord harmonica.