The Swan 10 hole diatonic harmonica in the key of C is ideal for both students and advanced players and is by far the most popular type of harmonica used today. It features 10 holes giving the player 19 notes and is designed to allow the player to play chords and melodies in a single key. The blues harmonica is perfect for solo playing as well as an accompaniment for guitar and other players. Suitable for all styles of music. C key. Includes carry case.