This harmonica has a diatonic scale in the lower row and a chromatic scale in the upper row, just like keyboard musical instruments. For ensemble use, play this harmonica for a sub-melody or rhythm part. The Soprano Single has 37 holes with a range of C1(middle C) through C4 in the key of C- three fully chromatic octaves. The holes are arranged like the keys on a piano - the 'white' keys on the bottom row and the 'black' holes on the top row. Solid brass reed plates contain the ultra precise laser tuned phosphor bronze reed system. Select hardwood is used for the body and the ergonomic, solid brass reed covers are finished in a super smooth high gloss black. This is playing comfort at it's best. The SS-37 comes in a velvet lined, leather covered wooden carrying case. This is a large harmonica - about 13 inches long, 2.25 inches wide, and 2 inches tall. The mouthpeice is about 3/4 inches tall.