Could I check if any parent here brought their kids to watch the 'bird who's afraid of heights' and have a video recording of the 123 song ? My girl is very interested in that song and keep humming it!

Perhaps you can try asking The Esplanade if they have any footage that they can spare? I remember my uni classmates requesting for footage years ago for a class and they acceded. Not too sure if they'll do the same for personal requests but no harm asking, yeah?