Layla by derek and the dominoes, is supposed to have been written by Clapton about his strong feelings for his friend George harrison’s then wife Patty.
there’s an urban legend that whilst Harrison wrote ‘while my guitar gently weeps’, he couldn’t quite get the solo right when the Beatles were recording it. McCartney and Lennon were apparently being a bit smartarsed about it, and eventually suggested ‘why don’t you ask your pal Eric (Clapton) to give it a try?’
After some time driving around looking for Clapton, he found him, fairly worse for wear and on cocaine. Arriving back at the studio, Clapton, with McCartney and Lennon watching on, nailed the solo first time, and it’s supposedly Clapton on the studio recording performing the solo.