Thanks Chris, appreciate the distinction (between melody and rhythum), although to be fair I'd been trying to learn the guitar for a few years before I totally realised it; I went for a lesson and the guys like 'no no NO' :)

I do still play the melody sometimes more as practice for picking notes and sight reading, or for fun when I'm playing solo with no singing or accompanyment, but it hasn't helped my rhythm practice so I avoid it a bit more now.

In this instance I was trying to understand the music and then went oh yeah, I just need to find a strum patter than works. But then wanted to understand it for umm learning / curiousities sake.

Appreciate your help.