There's never really any true way to know whether a Saturday Night Live sketch will become an instant classic or quickly fade from memory. But as Will Ferrell taught audiences on April 8, 2000, you can tilt the odds pretty drastically in your favor if you fall back on a Blue Öyster Cult hit, some banging cowbell and a fittingly bizarre Christopher Walken performance.

We're talking, of course, about the "More Cowbell" sketch, which imagines the recording session that produced the Blue Öyster Cult classic "(Don't Fear) The Reaper" — specifically the contributions made by cowbell player Gene Frenkle (Ferrell), aggressively encouraged by cowbell-craving producer Bruce Dickinson (Walken).

None of it ever really happened, and the whole thing was so surreal that it ended up being tucked away toward the end of the episode. But "More Cowbell" quickly took on a life of its own — a victory for Ferrell, who had to fight just to get it on the air.

"Every time I heard '(Don't Fear) The Reaper,' by Blue Öyster Cult, I would hear the faint cowbell in the background and wonder, 'What is that guy's life like?'" Ferrell told Rolling Stone in 2017.

The sketch was actually cut the first several times it was pitched for inclusion in an episode, but the idea lingered. "I held on to it for, I think, three months, until Christopher Walken was the host, and rewrote it for him," Ferrell added. "His odd rhythms fit so perfectly. He gave it that special sauce."

Naturally, word quickly filtered back to the members of Blue Öyster Cult, who were in the midst of a resurgence of sorts. Two years before the "More Cowbell" sketch aired, they released 1998's Heaven Forbid, the band's first album of new material in a decade; they were in the midst of prepping their next effort, 2001's Curse of the Hidden Mirror. While neither of those releases enjoyed the sales Blue Öyster Cult drew in their heyday, they continued to tour steadily. "(Don't Fear) The Reaper" remained a setlist favorite, and it had origins that weren't that far removed from the version Ferrell imagined.

"Ironically, it was similar to what happened in the skit," Blue Öyster Cult drummer Albert Bouchard told Fox5 New York. "We had put a whole bunch of overdubs on the song, and one of them was Randy Brecker — he put a flugelhorn part on it, or a trumpet or something, in the middle part. We didn't like it so I said 'Hey, I want to do a triangle in that part. That's what I want — I really hear a triangle in my head."

Watch Saturday Night Live's 'More Cowbell' Sketch

According to Bouchard, it was composer and jingle creator David Lucas who made the fateful call to add a cowbell instead of a triangle. "'I just want to hear that sound,'" Bouchard recalled Lucas insisting. "I said 'Okay,' so I play it, and I'm like 'Yeah, it's not working,' and he's like 'Oh, well, put some tape around it,' so I put some tape around it. I used, like, a timpani mallet, and everybody's like 'Yes, that's it!' So it's funny that [Ferrell] even noticed it, because it was mixed very low. You don't even really notice it in the track."

Little of this mattered to SNL viewers who were keyed into Ferrell's performance, which combined his typical aggressive clowning with the sort of desperate yearning for acceptance one might expect to see in a guy relegated to playing the cowbell in a rock band. That, coupled with eminently quotable Walken lines ("Guess what? I got a fever, and the only prescription is more cowbell"), helped the sketch snowball from late-night curiosity to viral phenomenon — and a part of Blue Öyster Cult lore.

Longtime frontman Eric Bloom admitted it took some repeat viewings to fully "get how hysterical it was," but he said he immediately appreciated the skit — and said he actually happened to see it air in real time. "It was a rare Saturday when we weren't on tour, so I saw it live," Bloom later recalled. "We had no idea. It was a jaw-dropping experience."

As for Ferrell, Gene Frenkle is just one among a series of lovable man-children in his repertoire, but he's proven thoroughly memorable over the years in spite of his limited screen time. As far as the comedian is concerned, the sketch's appeal has a lot to do with the stuff people don't necessarily notice while they're laughing — and it could also help explain why Ferrell was willing to reprise the character for a 2005 SNL appearance alongside Queens of the Stone Age.

"To the less-observant eye, the sketch was an excuse to let my belly hang out and wear tight '70s clothing," Ferrell told Rolling Stone. "But it really was about the exuberance of a guy who was given the green light to really express his art. Even though it's funny, it was rooted in something real."

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