Returning home from a busy shift at CTV News Online, I'm hurtling westward in the Tube. Three altish-looking teen girls -- with piercings, tats and obviously dyed hair -- are off to my right on the opposite side of the car.

Then one girl says to the other two: "Have you seen my latest?"

As the other two crowd around, she unzips the front of her black knit dress and pulls it open to reveal the large metal stud now fixed in her flesh in the dead-centre trough of her cleavage -- much of which was exposed by this exercise (and which was not unsubstantial).

Much ooh-ing and ah-ing by her pals.

Me? I tried to be discrete.

Another thing I found interesting (although not as interesting) was one girl was wearing a Pink Floyd: The Wall hoodie -- and they were talking about Beatles tunes.

Let's say these girls were 18. Their parents would likely be my age (do the math).

Their parents would have probably graduated high school in the late 1970s, a number of years after the Beatles called it quits. The Wall was released in 1979.

If my age estimate of these girls is correct, they were born about eight years after The Wall was released, and about 17 years since the Beatles broke up. And its now about 26 years and 35 years since those events.

That's a long way of saying some of the classic rock that seems to be coming back in vogue (from what I can see and hear) in some circles might not have even been their parents' music -- which maybe is key.

There might be an as-yet undiscovered musical styles revival algorithm out there that can predicts when teens will rediscover music. My theory? Somewhat behind their parents' generational tastes -- BUT NOT WHILE THEIR PARENTS ARE LISTENING TO IT.

Under no circumstances can teens (well, the cool ones, anyway) and parents enjoy the same music at the same time.

While there's lots of 80s music around (and some attempts to kickstart a 90s nostalgia movement), I would suspect that's met with indifference by the kids.

I would note (although I'm not sure to what purpose) that in certain establishments in West Toronto a couple years ago, the Velvet Underground seemed to be everywhere (which is a good thing).

I'm too tired for tonight's purposes to comment much further, but I love musing about all these little swirls in the river of our collective pop culture.