Six years ago, Glenn Schellenberg decided to do an experiment.

Schellenberg works at the University of Toronto, where he studies the psychology of music. The idea behind his experiment couldn’t have been more straightforward: He simply wanted to play music for people and get them to rate how happy or sad that music made them feel.

These two emotions — happy and sad — are relatively easy to identify in music, and though there are different ways for music to convey emotion (through lyrics or what kind of instruments are used), Schellenberg says the tempo of a song and whether it’s in a major or minor key often strongly influences which emotion the song conveys.

“Happy-sounding songs typically tend to be in a major key, and they tend to be fast, [with] more beats per minute,” he says. “Conversely, sad-sounding songs tend to be slow in tempo, and they also tend to be in a minor key.”

So Schellenberg sat down with a grad student and told him to find both happy-sounding fast music in a major key and sad-sounding slow music in a minor key. Essentially, they were looking for emotionally clear music that they could play for their future research subjects.

But while the grad student had no trouble finding fast, happy-sounding music in a major key when he looked at older musical eras — from the classical period up through the 1960s — it got a lot harder when it came to contemporary pop music.

Read more and/or listen here . . .