When Willow Yamauchi saw an old, dilapidated piano in her alleyway in East Vancouver, she didn't think much of it, but when she saw another months later, she knew there had to be a story behind the occurrences.

"And I thought why would someone do that to a piano?" she told CBC News about her new documentary on CBC Radio One called End Notes.

Through her research, she found out that many pianos built a century ago have come to the end of their playable lives. That, combined with the housing crunch in Metro Vancouver, has led to them showing up in local landfills at an alarming rate.

Why are there so many smashed up pianos in the dump? 1:23

"It's terrible, it's terrible," she said.

"People feel emotional about pianos. It's almost like a family pet. People have grown up with them, it's been part of their family, they've had happy birthday and Christmas songs around them," added Yamauchi.

"So when people find out that they can't really fix them, that there's no home for them and that they have to go to the dump — terrible thing, really really sad."

Yamauchi found as many as four pianos are ending up in landfills each month in Metro Vancouver, and hundreds are for sale or even listed for free on Craigslist.

Aging pianos can be restored, but a complete rebuild of the thousands of moving parts inside can cost up to $25,000.

"What's happening is that most people can't afford to fix them or they don't fix them or they're moving to small apartments and they don't have room for a 700lb broken antique," she said.

"They're 100 years old, we've got a housing crisis in the Lower Mainland, people are wanting electric pianos that they can plug in and not have to listen to their kid playing, they can get a head-set."