Pronunciation of "I" vowel name in fast speech
Solution 1:
Welcome to the site! There is no real 'right' way to pronounce I in fast speech, let alone song. I can only say that the allophones you have heard, in the given positions in those sentences, are quite common. There might be other options as well.
The faster a vowel is pronounced, the more likely it is to be reduced, from /aɪ/ to /a/ or /ʌ/ and even /ə/. I'd like to think reduction is much less common in classical music, but that is probably an exaggeration.