Manhattan College of Music professor and Skilled double bass participant Timothy Cobb educating a bass lesson during the late 2000s. His bass has a minimal C extension using a metal "equipment" with buttons for taking part in the pitches about the extension. g. important or minor) of the dimensions in https://vuf.minagricultura.gov.co/Lists/Informacin%20Servicios%20Web/DispForm.aspx?ID=3908854