Clarinet
One kind of keyed clarinet is called the Albert system.  Another kind is called the Boehm system. The Boehm clarinet is much used by classical orchestras and by jazz musicians. In North America and other Western countries, the most popular clarinet is the clarinet pitched in B flat. This means that if a clarinet player plays a note that is written as a C, it sounds like a B flat on a piano. The B flat clarinet is used in concert, marching, and school bands.  Musicians in orchestras also play the A-clarinet (a semitone lower), the sopranino E flat clarinet (a fourth higher) and the Bass_clarinet  in B flat (sounding an octave lower).