This music makes me sleepy

Lately, Tobin has seemed to be resisting sleep more after feedings or after being up for a while. One of his amusing/frustrating habits is the timing of his startle reflex. He'll be newly asleep, maybe a light sleep, and then startle as if he was being dropped off the bed. I know it's natural (yes, I looked it up), but the timing of it is uncanny. It looks like this if I try to put it into words:

Peaceful, sighing, drifting, drifting, peaceful -- I'M FALLING OH MY GOSH! . . . two minutes elapse.
Sighing, peaceful, calm, I am a cloud floating on the -- WHOAH! AM I BEING DROPPED OR WHAT?! . . . two minutes elapse. And so on for between four and twenty minutes.

Today, after one of those sessions, I brought him into the living room and put him in his bouncy chair. I was reorganizing some CDs and put the final movement of Brahms's first symphony on while I was doing it. Tobin was calm and peaceful almost immediately; he was asleep by the time the woodwinds took over the main theme. I like to think he's processing the music personally and finding it soothing, but I know it may just be a confluence of other soothing factors, one of which is probably the ceiling fan that was directly over his head. At the very least, it was nice to associate a piece of music I really like with him finding the rest that had eluded him for a while.