What are the rules for separating song lyrics into syllables?

If we were to take the Beatles song I would be tempted to write this as 'Yes -ter -day', but I suspect that if this was in a classical choral score it would be more appropriately expressed as 'Ye -ster -day', on the basis that there would be excessive sibillance with the first syllable ending in 's'. It's a lot more clear cut if you sing in Italian, but the general rule in English seems to be to end the syllable with a vowel sound if possible and then transfer the following consonant to the next phrasing.

OK, so it's only folk music that I typically fiddle with, but does anyone know what the 'correct' rules are please?

I have a vague feeling that we've discussed this before but I can't find any reference to it.

Regards, John