Prior to 1969 there was no official singles chart;[1][2][3] however, The Official Charts Company and Guinness' British Hit Singles & Albums regard the canonical sources as New Musical Express (NME) before 10 March 1960 and Record Retailer from then until 15 February 1969 when Retailer and the BBC jointly commissioned the British Market Research Bureau (BMRB) to compile the charts.
[1][4] The choice to use Record Retailer as the canonical source for the 1960s has been contentious because NME (which continued compiling charts beyond March 1960) had the biggest circulation of periodicals in the decade and was more widely followed.
[1] In 1969, the first BMRB chart was compiled using postal returns of sales logs from 250 record shops.
The Beatles' song "She Loves You" became the best-selling single of all time in 1963, a record it held until 1977 when band member Paul McCartney's new band, Wings, surpassed it with "Mull of Kintyre".
Although The Righteous Brothers first released "Unchained Melody" in August 1965 it had more success after being re-released in the 1990s reaching number one and selling over one million copies.