John Alec Entwistle (9 October 1944 – 27 June 2002) was a British musician, songwriter, singer, film and music producer, who was best known as the bass guitarist for British rock band The Who. He was the only member of the band to have formal musical training. His aggressive lead sound influenced many rock bass players. He was inducted into the Rock and Roll Hall of Fame as a member of The Who in 1990.
John Entwistle's instrumental approach used pentatonic lead lines, and a then-unusual trebly sound ("full treble, full volume") created by roundwound RotoSound steel bass strings. He was nicknamed "The Ox", as well as "Thunderfingers" – because his digits became a blur across the four-string fretboard. He had a collection of over 200 instruments by the time of his death, reflecting the different brands he used over his career: Fender, Danelectro, and Rickenbacker basses in the 1960s, Gibson and Alembic basses in the 1970s, Warwick in the 1980s, and Status all-Carbon fibre basses in the 1990s. In 2011, a Rolling Stone reader poll selected him as the greatest bassist of all time. The Biography Channel has declared that John Entwistle is considered by many to be the best bass guitarist that ever lived, and that it is often said that he did for the bass what Jimi Hendrix did for the guitar.