Large, low-pitched musical instrument of the violin family, held between the performer's knees. It has four strings tuned C G d a (C = two C's below middle C; a = the A below middle C). Its range extends over more than four octaves. The earliest surviving cellos are two from the 1560s by the Italian violinmaker Andrea Amati.
Until the late 18th century the cello was primarily a supporting instrument, playing bass lines and adding fullness to musical textures. During the baroque era unaccompanied cello suites were composed by Bach, as were cello concertos by Vivaldi and Boccherini. In the 19th century, works for the cello included concertos by Brahms and the Dvorak. In the 20th century, composers such as the Prokofiev and Shostakovich further explored its solo capabilities. The most prominent 20th-century cellists include Pablo Casals, Yo-Yo Ma, Gregor Piatigorsky and Mstislav Rostropovich.
Read more on Wikipedia.