I sang a lot to ZK in his first two years - on the way to school, in bed, doing random things... In fact, I used to sing until he fell asleep. Or I fell asleep. It didn't matter coz he would just lie there quietly, asleep or awake. I could sleep next to him and he would eventually sleep. He would sing in the day but it was a lot of input with little output when it was all dark.
On the other hand, ZY gave me output all the time. Since he was verbal, he would sing along happily if I sang to him in bed - no sign of sleepiness!! So recently, all I sang was the sleeping song I made up. He often asked for repeats. Just now, he made me sing it some five times. I thought that was it but I was wrong - he launched into song by himself! He sang the 12345 song two or three times, with actions...
Taken while ZY was still having his cute voice
(just ignore my tak glam look...)
It was super cute but I was fretting that he still wasn't sleeping at 8.30 pm! But then I recalled a few recent instances when he would be singing loudly one moment and dozing off the next, and I got hopeful... Indeed, he started to drift off! But before I could scream a silent YEAH, ZK came into the room and ZY bolted into a sitting position, argh!
I wonder how monkey will be like when it comes to lullabies. Would be nice to have a baby who sleeps to my voice like ZK (though that might be bad when I nag??!) but also fun to hear him sing excitedly like ZY :)