It wasn't only his guitar which required tuning - his voice on the first song was even worse - if you can, listen to the sustained notes. Fortunately the second song was better. If you're going to perform on a live broadcast, there is really no excuse. If you must leave your instrument to others, a simple chord before you start will prove whether or not its still in tune.

I remember seeing Don McLean at the Free Trade Hall back in the 70s. Unfortunately, I was more impressed with the support act - Messrs Robin & Barry Dransfield.