Like many on the autism spectrum, Ryan craves routines. He has many, and collectively they form the pillars of his days. Everything from the time he gets up, to the breakfast he eats, to how he budgets his free time before school, to when he does his homework, to how he watches hockey in the evenings, vary little from day-to-day.

These routines keep him regulated. They change from time to time, and when a change is made, it’s as if the previous routine is immediately forgotten — like it never existed at all.

If there is one part of his daily routine that is immune to change, it is his bed time ritual. We almost never have to remind Ryan about bed time. At the appointed hour, he comes racing up the stairs from where he was watching hockey on the basement TV. He brushes teeth, climbs into his San Jose Sharks-themed bed in his Sharks-themed room and announces, “I’M GOING TO BED!”

The last part is our cue to come in and say goodnight, and in a phrase he has mostly outgrown but still drops occasionally to our very great delight, “tuck him up.”

We fix the covers on his bed, where the sheets have invariably become completely un-tucked from the mattress, arrange his weighted blanket, turn on his fan — everyone in our house is a devotee of white noise — and start his bedtime music.

For as long as any of us can remember, since it was played on a CD coming the boombox we bought for his nursery, that bedtime music has been a collection of instrumental lullabies. Ryan never questioned it or asked to change it and it seemed to help settle him, so we never thought to change it. When Ryan wakes in the night, he will sometimes restart the music to settle himself.

These days Ryan’s music plays from an old iPod connected to a portable speaker. The songs are on Ryan’s iPad so he can keep his routine as normal as possible when we travel.

Ryan has also become quite a music fan and has embraced a lot of my favorite artists. He takes an iPod with him just about everywhere except school. He listens mostly to a rotating playlist of about 15 songs, mostly U2 oldies from the Boy/October albums.

I’ve tried to expose him to even more music, but getting anything added to his playlist is like prying open a jammed door. Once in a while, I succeed but mostly my efforts end in frustration.

Last week I was putting Ryan to bed. I tucked him up. I turned on the fan. I went to start the music, when he had a request.

“Dad, can I listen to U2 at bedtime?”

For some reason, this struck me as a bad idea. I suggested with stick with routine and soon the familiar notes of classical music played.

He persisted. I said perhaps on the weekend we could put together a new bedtime playlist of slower, mellower songs that he likes.

And then I forgot about it. The weekend came and went. He continued to fall asleep to his traditional music.

Monday night, he had a confession.

“Dad, when [our sitter] was here, I fell asleep to U2!”

I laughed. He had a huge smile on his face, one that suggested he was proud of himself for getting away with something, but not something so bad that he didn’t want to tell me about it.

I looked at my 13-year-old son, and thought for a moment about how remarkable it once would have been for him to do any one of: a) expressing his preferences; b) breaking a rule (no matter how minor); and c) telling us about it. He had just done all three in one sentence, and it wasn’t surprising.

There’s no reason for me to resist changes in routine except in a futile attempt to hold back time. After all, the routines are to give comfort and regularity to him, not me.

Ryan will announce he’s ready for bed at the appointed hour tonight, and well go into his room to say goodnight. We’ll tuck him up in. We’ll start his fan. And then I’ll let him tell me what he wants to listen to. Rock and roll as a lullaby? Let’s make it part of the routine.