I came across this last year. I didn't realise that Phil Everly recorded the original version of The Air That I Breathe, which of course The Hollies had a big commercial hit with. I like both versions very much, and apparently The Hollies liked Phil's version so much when they heard it that they felt that they should record it too.
Phil's version is very stripped down production-wise in comparison to the Hollies version, and his voice is very plaintiff. I think I prefer the original but they are both great.

