Manhattan School of Music professor and Skilled double bass participant Timothy Cobb training a bass lesson during the late 2000s. His bass contains a low C extension that has a steel "equipment" with buttons for playing the pitches around the extension. A melody (also referred to as a "tune") http://waylonojcul.tinyblogging.com/Helping-The-others-Realize-The-Advantages-Of-Recording-Studio-32634166