List of best-selling singles

Columns: Artist | Single | Released | Sales ( in millions )
Bing Crosby | White Christmas | 1942 | 50 | Elton John | Candle in the Wind 1997 | 1997 | 33 | Mungo Jerry | In the Summertime | 1970 | 30 | Bing Crosby | Silent Night | 1935 | 30 | Bill Haley & His Comets | Rock Around the Clock | 1954 | 25 | Whitney Houston | I Will Always Love You | 1992 | 20 | Elvis Presley | It 's Now or Never | 1960 | 20 | USA for Africa | We Are the World | 1985 | 20

Example questions:
The artist who has worked with Bernie Taupin since 1967 re-released an altered 1973 best-selling single as a tribute to who ? | What blues format is the best-selling single by this band founded in 1952 and led by a former country music artist ? | The second highest-selling physical single of all time is by an artist with what given birth name ? | Who wrote the best-selling single of this duo formed in 1977 by two female Spanish artists ?

Answers:
Diana , Princess of Wales | 12-bar blues format | Reginald Kenneth Dwight | Frank Dostal and Rolf Soja