CapriUni:

I was too brief. The specific songs I was referring to are the 'sentimental' variety. 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.

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

Lullibies are, I think, a special category; bound up in the hard wired reactions babies have to human faces, voices, and so on.