THE WIKI:
“Crazy Little Thing Called Love” is a song by the rock band Queen, written by Freddie Mercury in 1979. The song peaked at number two in the UK Singles Chart in 1979, and hit number one on the Billboard Hot 100 in the US on 23 February 1980, remaining there for four consecutive weeks.
As reported by Freddie Mercury in Melody Maker, 2 May 1981, he composed “Crazy Little Thing Called Love” on the guitar in just five to ten minutes.
“‘Crazy Little Thing Called Love’ took me five or ten minutes. I did that on the guitar, which I can’t play for nuts, and in one way it was quite a good thing because I was restricted, knowing only a few chords. It’s a good discipline because I simply had to write within a small framework. I couldn’t work through too many chords and because of that restriction I wrote a good song, I think.”
Freddie Mercury
The band’s drummer Roger Taylor added in an interview that Mercury wrote it in 10 minutes while lounging in a bath in the Bayerischer Hof Hotel in Munich during one of their extensive Munich recording sessions. A rockabilly inspired song done in the style of Elvis Presley, Mercury took it to the studio shortly after writing it and presented it to Roger Taylor and John Deacon. The three of them, with their new producer Mack, recorded it at Musicland Studios in Munich. The entire song was reportedly recorded in less than half an hour (although Mack says it was six hours). Having written “Crazy Little Thing Called Love” on guitar and played rhythm on the record, for the first time ever Mercury played guitar in concerts, and one of his most notable performances took place at Live Aid at Wembley Stadium, London in 1985.