The cello (pronounced / CHEL-oh; plural cellos or celli) is a bowed string instrument with four strings tuned in perfect fifths. It is a member of the violin family of music instruments, which also includes the violin, viola and the contrabass.

The word derives from the Italian 'violoncello'. The word derives ultimately from vitula, meaning a stringed instrument. A person who plays a cello is called a cellist. The cello is used as a solo instrument, in chamber music, in a string orchestra and as a member of the string sectionof an orchestra. It is the second largest bowed string instrument in the modern symphony orchestra, the double bass being the largest.

Cellos were derived from other mid-to-large sized bowed instruments in the 16th century, such as the viola da gamba, and the generally smaller and squarer viola da braccio, and such instruments were made by members of the Amati family of luthiers. The invention of wire-wrapped strings in Bologna gave the cello greater versatility. By the 18th century the cello had largely replaced other mid-sized bowed instruments.

The name Cello is an abbreviation of the Italian violoncello, which means "little violone",or referring to the violone ("big viol"), the lowest-pitched instrument of the viol family, the group of string instruments that went out of fashion around the end of the 17th century in most countries except France, where they survived another half-century or so before the louder violin family came into greater favour in that country too. The viols have enjoyed a vigorous revival in the 20th and 21st centuries. Thus, the name carries both an augmentative "-one" ("big") and a diminutive "-cello" ("little"). By the turn of the 20th century, it had grown customary to abbreviate the name violoncello to 'cello, with the apostrophe indicating the six missing prefix letters.[1] It now is acceptable to use the name "cello" without the apostrophe and as a full designation.[1] Cellos are tuned in fifths, starting with C2 (two octaves below middle C) as the lowest string, followed by G2, D3, and A3. It is tuned the same way as the viola, but an octave lower.

The cello is most closely associated with European classical music, and has been described as the closest sounding instrument to the human voice.[2] The instrument is a part of the standard orchestra and is the bass voice of the string quartet, as well as being part of many other chamber groups. A large number of concertos and sonatas have been written for the cello.

Among the most well-known Baroque works for the cello are Johann Sebastian Bach's six unaccompanied Suites. The Prelude from the First Suite is particularly famous. From the Classical era, the two concertos by Joseph Haydn in C major and D major stand out, as do the five sonatas for cello and pianoforte of Ludwig van Beethoven, which span the important three periods of his compositional evolution. Romantic era repertoire includes the Robert Schumann Concerto, the Antonín Dvořák Concerto as well as the two sonatas and the Double Concerto by Johannes Brahms. Compositions from the early 20th century include Edward Elgar's Cello Concerto in E minor, Claude Debussy's Sonata for Cello and Piano and unaccompanied cello sonatas by Zoltán Kodály and Paul Hindemith. The cello's versatility made it popular with composers in the mid- to late 20th century such as Sergei Prokofiev, Dmitri Shostakovich, Benjamin Britten, György Ligeti and Henri Dutilleux, encouraged by soloists who specialized in contemporary music (such as Siegfried Palm and Mstislav Rostropovich) commissioning from and collaborating with composers.

Today the instrument is less common in popular music, but was commonly used in 1970's pop and disco music.[citation needed] Today it is still sometimes featured in pop and rock recordings, examples of which are noted later in this article. The cello has also recently appeared in major hip-hop and R & B performances, such as singers Rihanna and Ne-Yo's performance at the American Music Awards.[citation needed] The instrument has also been modified for Indian classical music by Nancy Lesh and Saskia Rao-de Haas.[3]