He claims he's nocturnal. Maybe he has something there.
Once, a few years ago, he actually sang himself to sleep. He was lying on the floor (he maintained it was more comfortable than his bed - and whatever - I just wanted him to fall asleep - at that point, I didn't care where) and he was singing when I walked past his room. I walked by again about a minute later and he was fast asleep.
But what he really likes is for me to sing to him at night. (This doesn't happen too often). When he was a baby and I'd try to sing to him, he'd put his hand over my mouth. Okay - fine, I got the message. But, now he likes it. And there is one song in particular he likes. "Too-ra-loo-ra-loo-ra" - also known as "An Irish Lullaby." I only sing him the refrain, because it's the only part I know. And if I'm not available to sing it to him, he's been known to sing it to himself.
So, I sing him a verse or two when I can, because he's seven years old now - and it won't be long before he won't want me singing to him (just like when he was a baby.)
Too-ra-loo-ra-loo-ral, hush now, don't you cry!
Too-ra-loo-ra-loo-ral, that's an Irish lullaby.
The full song can be found here.