When Honda produced a musical road in Lancaster, California a few years ago, I linked to their commercial and developed a lesson that included it. A Blog of Phyz post was duly posted.
The off-key result (and a bit of auto-tuning) bothered me. And I certainly didn't keep that a secret. I assumed it was an implementation error of some sort, and tried to invoke the notion that, "It's not that the dog sings well, it's that the dog sings at all!"
Creative science YouTube content creator, Tom Scott, did the legwork, er, wheel work to get to the bottom of this grooviness gone awry. It boils down to "centers" vs. "gaps". Take a look.
If you spend time distinguishing between random and systematic error, you'll want to add this to your curriculum there.
Why California's Musical Road Sounds Terrible
Scott refers to his source: Caltech's David Simmons-Duffin. Here's the well-crafted and thorough article posted at DavidSD.org way back in 2008. It really is well done, and he calls out Honda for auto-tuning the last two notes of the road, as did I. Spend some time and enjoy this post:
Honda Needs a Tune Up