I would say neither, Phil.

Bellamy was a self-conscious performer, God knows, but I doubt his artistic ego worked quite that way.

I think it more likely that, like many singers working in the traditional idiom, he created the song and his way of singing it without much reference to anyone except his audience, or anything but the lyrics and the story they tell. After that, every performance reflected the original concept.

Also, many singers have a fast-and-loose relationship with metre, which they basically don't need if they sing a capella or accompany themselves. What's an extra beat between friends? Who cares if I cut off the two-beat rest at the end of the line, if there's no guitarist at my elbow to click her tongue in annoyance because I haven't left room for her bass run?

As for the issue of grim songs with bouncy tunes -- well, yer typical ballad tune drops trippingly off the tongue while the lyrics distribute drowned lovers, murdered babies, beheaded wives and defeated armies all over the landscape. That's folk!