Say what you want about “Glee,” but it’s hard to deny the historical impact — the show ushered in a new era of musical television. And Cory Monteith, who died Saturday at age 31, was an integral part of “Glee’s” reach since the beginning.

Back in May 2009, Fox took the unique step of airing the pilot months before the show officially premiered in September, and “Glee” hype built until the fall. If you were to point to a reason why, it was likely because of the definitive performance of the pilot, and possibly the entire series: Monteith’s song with Lea Michele, as they closed out the episode with a dynamic duet of Journey’s “Don’t Stop Believin’.”

The song played all summer, went platinum, and came to represent the show itself. It sent a triumphant message to the underdogs, which has always been “Glee’s” underlying theme — and why it initially connected with so many viewers.

Monteith, who played one of the lead roles as football player-turned glee club member Finn, was on the show for all four seasons (though took a short break when he went to rehab earlier this year). The series has had its ups and downs — but when Monteith was on screen, he was a reminder of its earnest, and best, early days.

Here are some of Monteith’s most memorable performances on the show:

“Man in the Mirror”

“I’ll Stand By You”

“It’s My Life/Confessions”

“Faithfully” (audio only)

“You Can’t Always Get What You Want” (audio only)