Can't actually think of very many traditional songs with silly/inane words...apart from the Whistling Gypsy Rover which I mentioned on the other thread, none spring to mind...and none at all with weak melodies (presumably because virtually by definition, if they weren't singable they wouldn't have survived beyond the lifetime of their creator).

Melodic strength = Can you hum the tune back to yourself after (say) an hour since hearing it for the first time?
Intelligence = Not banal, inane, or gratuitously obscurantist.

(BTW thanks for your message re Bellamy- will respond later today/tonight)