Blues Session Natural Minor. Covers: Chrom. Diatonic Bluesharp with Plastic Comb in Extra Tuning Natural Minor - Labeled in Cross Harp. This tuning allows to play very soulful minor tunes in Blues and Jazz without having to bend the notes too much. Since in theory this tuning can only be played as the Minor Scale in second position, we have decided not to define the key of this harmonica following the usual convention. In this case the designation is by the basic note of the Nat.Minor Scale, hole 2 draw - so a harmonica that normally would be called a C after the frist hole blow note would be a Natural Minor in G.