“Catchy Song” has an airy sheen thanks to production by the D.J. Dillon Francis and vocals from T-Pain and That Girl Lay Lay. In a phone interview, Lajoie talked about the difficulty of following up the first “Lego Movie” hit song, “Everything Is Awesome,” what it takes to make an earworm and why he doesn’t feel bad for parents who have to listen to it over and over again.

How did you end up writing “Catchy Song?”

I’d wanted to do this kind of thing for a long time. But the opportunity to write music for an animated movie is few and far between, and it usually goes to Broadway people. I didn’t know whether I’d be good at all. But I wanted to at least try. The filmmakers liked my stuff enough to let me take a crack at it.

What was your objective with it?

At first we were going more in the direction of a song that is supposed to drive you insane, something that sort of feels creepy and brainwashy.

And so I thought about it for a while and then, one day I was showering and I start screaming, “This song’s gonna get stuck inside yo! This song’s gonna get stuck inside yo!” So I wrote an annoying version of that. But eventually the movie’s story changed and it needed to be a somewhat enjoyable song.

Was it daunting to think about how to follow up “Everything Is Awesome”?

Yes, there’s no way to make a more annoyingly catchy song than “Everything Is Awesome.” So we thought, let’s look at the audience and acknowledge that we know this in an impossible task, and let’s lean into the meta-ness and take it one step further. We wouldn’t necessarily have to write a catchier song, we would just say that the song is super-catchy.