To complement the chord harmonica, Suzuki offers the 39-hole SBD-39 orchestral double bass harmonica for ensemble play. Special voicing or tuning gives the double bass harp a beautiful, rich, projecting sound quality. The upper low notes are tuned to a C# scale and the lower low notes are tuned to a C scale. You can cover a full two chromatic octaves. Each note has two reeds which are an octave apart. Double reeds create not only a deep and rich sound, but also a crisp sound with a projecting edge. The player has ultimate control for just the right effect. Each harmonica comes in a beautiful velvet lined wooden case with carrying pouch.