Clarinets actually comprise a family of instruments of differing sizes and pitches. It is the largest such instrument family, with more than a dozen types. Of these many are rare or obsolete, and music written for them is usually played on one of the more common size instruments. The unmodified word clarinet usually refers to the B soprano clarinet, by far the most common clarinet. (See "Clarinet Family"). A person who plays the clarinet is called a clarinetist or clarinettist.