I’ve always thought that the best relationships are built on the silly little things.

Don’t get me wrong: In a marriage or other long-term arrangement, it’s important to agree on the big things, too. But the little things—like what type of wine you like or what kind of music you listen to on a road trip—make an enormous difference in your day-to-day sanity and happiness.

When it comes to what I love about watching my husband with our 3-year-old, the same seems to hold true. Sure, I could name a dozen “big” parenting things that he does that are awesome. But the one random thing that really tugs at my heartstrings is their bath-time routine. Before my son gets sudsy, the two of them put on a full-on rock show—literally—and it’s music to my ears.

You see, our little guy is all about music. No, really, it’s to the point of obsession. He talks about wanting to play in an orchestra someday, he gets ridiculously excited when he sees a double bass or a tuba, and he regularly requests to watch John Williams conduct Star Wars on YouTube. His mini guitar is never far from him, and the only thing he wanted from Santa this year was a microphone.

I foster his interest with music classes, lots of singing and Amazon Local deals for various performances (Cinderella at Lincoln Center, with a full ballet and orchestra, for $19—score!), but my husband has his own style with our baby Mozart.

On the nights that he’s on bath duty, he puts on his iTunes playlist and turns it up. Way up. From the very first chords of Rush’s “The Temples of Syrinx,” my son lets out an excited squeal and runs straight to his dad. Often, he’ll get there and say, “Wait a minute! I forgot something!” then race back into the living room to grab his guitar.

He dances around like David Bowie, showing off his “dance moves” while in his skivvies and with his hair askew in true rock-star style, and sings whatever my husband has selected for the night. But these aren’t your regular kiddie tunes, as you may have guessed from the favorite above. No, aside from Rush, we’re talking Slayer, Iron Maiden, Baby Metal, Joan Jett, Bob Marley and Katy Perry.

My husband has created quite the eclectic little groupie, yes, but he’s also created this wonderful little space just for the two of them. Mommy is usually allowed to join this dynamic duo—and I love doing it—but on most nights, I try to keep my distance.

My son and I can have other moments together. But this time with his dad? It’s their thing. Their special time. And it’s the type of random memory that my son will recall in the most wonderful way years from now.

That’s the amazing superpower that all parents have, should they choose to use it wisely: turning the littlest things into the biggest moments imaginable.

So yeah, it’s the little things that make my husband a rock star to me—and way better than a rock star in the eyes of our adoring 3-year-old. He’s Dad, and he totally rocks.