I was listening to "Any Friend of Diane's" by Weezer and was wondering about the varied pronunciations of of.
Any friend of Diane's is a friend of mine.
As rendered in the song (it's the first line, linked above), both of's sound something like /ə/ or more open, but it's inconsistent, sometimes the consonant is there. I assume the dropped consonant and increased vowel openness is because it's sung and slurring the vowel into the next word lets you save some time. However, if I speak that phrase, I'm often slurring the second of into just a vowel (friend /ə/ mine) but keeping the first as closer to /əv/.
Is this a regional/dialect thing? An implicit of → o' contraction for more common "of X" pairings?