Diatonic, single reed harmonicas feature reeds tuned to produce the natural notes of the musical scale - without any additional sharps & flats (a diatonic instrument). They are ten-hole instruments with the four middle holes comprising a complete eight-note octave - the holes on either side permit chord playing. They are capable of producing bending & overblowing, which will allow the player to achieve sharps and flats. The MS harp with the wood body - and old favorite! Wood body construction gives the blues harp the raw blues sound that so many professionals demand.