The standard, highbrow obituary of Pierre Boulez would highlight the obvious facts and benchmarks of his life.

They'd mention that he was born in France in 1925. That he conducted, sans baton, many of the world's leading orchestras. And that Boulez was known as an avant-garde composer.

But I want to hightlight his collaboration with someone you may not expect: Frank Zappa.

Yeah, that Frank Zappa. Leader of Mothers of Inventions. Freak Out! And the song with that all important message — "Don't Eat the Yellow Snow."

Zappa was striving to get his orchestral music played in Europe. He wanted to be treated seriously. Sure The Royal Philharmonic Orchestra had a hand in the soundtrack to 200 Motels, but Zappa wanted more. A brief collaboration in 1970 with Zubin Mehta went nowhere.

In the 1980s, Boulez stepped in. Zappa sent the maestro some scores. Boulez accepted. The result? Boulez Conducts Zappa: The Perfect Stranger. It was released in 1984.

For some in classical AND rock circles, the collaboration was perfectly strange.

But as we look back, maybe Zappa and Boulez weren't that far apart. Afterall, Zappa was firmly ensconced in avant-garde rock.

While Boulez, always looking for the next musical challenge, was again, known as the avant-garde composer.

Need a further example?

Here's Frank Zappa's song "Dupree's Paradise," performed live by Mothers of Invention in Stockholm, 1973.

This track was never recorded in the studio UNTIL Boulez got his hands on it.

Now, both men are gone. But I'm hoping the musical conventions they broke will carry on and that they'll inspire others to do the same. It keeps life interesting.

A previous version of this story misstated when Boulez died.