From mack/misophist: To me, the interplay of consonant and vowel sounds is a part of the over all musicality, on a par with the quality of the singer's voice or the instrument's timbre.

Indeed. As a long time student of English literature, I know this to be true. "Ordinary" spoken language, if crafted well, can be as musical as any cantata by Bach. Shakespeare was certainly a musical writer, as were more modern folks like Emily Dickinson and W.B. Yeats.

I think I first found this article on another Mudcat thread last summer, about how the twelve tone scale itself may be hard wired into our brains -- that the jumps from note to note match the tones we naturally produce when speaking. So maybe singing is what naturally happens when we put more physical and emotional energy into our expressions.

As far as your specific question goes, the answer is undoubtedly yes. The real question is 'How do you tell?'.

Ah, yes. Hence the question that I thought might spark some interesting Mudcat discussion. ;-)