The key to the Bert Weedon quote is the name of his book, Play in a Day. This was a book first published in the early sixties, I think (anyway, that's when I read it). It spawned a series and lots of spin-offs - a publishing phenomenon; it's still in print. Here's a short extract from the Amazon page:
Read more here: Bert Weedon's Play in a Day: Guide to Modern Guitar Playing Guitar: Amazon.co.uk: Bert Weedon: BooksProduct Description
"Bert Weedon's Play In A Day" remains one of the world's most successful guitar tutors. It is as much as legend as the stars that have learnt from it including Eric Clapton, Mike Oldfield, Paul McCasrtney, George Harrison, John Lennon, Sting, Brian May, Pete Townshend and many, many others! "Play in a Day" is easy to use, with plenty of tips for selecting the right guitar, the correct amplifier, how to hold your instrument and plenty of tunes and exercises to get to grips with.
Of course nobody learns to play the guitar in a day - hence the reference to the TDA (a reference to some UK legislation that controls what a trader can say in order to sell something): Trade Descriptions Act 1968 - Wikipedia, the free encyclopedia . The joke is anachronistic; Bert Weedon's book pre-dates the TDA; but who cares?
I don't recognize the 'Clark/Kearns' pair, but I expect they're lyricists - often much less famous than their songs.
Student or Learner