Simplify the following text for a Grade 10 native English-speaking person.
Original: Victor Marlborough Silvester OBE ( 25 February 1900 â `` 14 August 1978 ) was a English dancer , author , musician and dance band leader whose records sold 75 million copies from the 1930s through to the 1980s , and a significant figure in the development of ballroom dance during the first half of the 20th century .
Simplified: Victor Marlborough Silvester OBE ( 25 February 1900 â `` 14 August 1978 ) was an English dancer , author , musician and dance band leader . He was a significant figure in the development of ballroom dance during the first half of the 20th century , and his records sold 75 million copies from the 1930s through to the 1980s .