Do you remember the voice messages in which I sing-song (or hummed along a song, could be.) tunes?
Do you remember the tunes I left for you on your voice mail (box).?
Do you remember that song that I intoned to you by voice messages?
As for the second sentence just reverse the position of "through" and "night", and insert "the" before then.
"when I rocked you through the night, cuddling you and putting you to sleep."
Or (perhaps better, given the situation) "when I used to rock you through the night,..."/"when I would rock you through the night,..."
Anyway, sometimes - most of the time, there´s more than a way to express things in English. So, let´s wait for more comments/suggestions on this one.