Nobody agrees who actually played the cowbell on Don't Fear the Reaper
The cowbell on Blue Oyster Cult's biggest hit became so famous that Saturday Night Live built a whole sketch around it. Yet the people in the studio cannot agree on who played it. The bassist says his drummer brother did, the producer says he did, and the singer Eric Bloom claims it too.
Lead guitarist Donald Roeser, known as Buck Dharma, wrote and sang the song while imagining that he might die young. He meant it as a love song in which love outlasts the lovers' physical lives, using Romeo and Juliet as a couple united after death. Some listeners heard a murder-suicide pact instead, a reading Dharma found appalling; his message was not to fear death, not to seek it.
The recording caught fire quickly. The riff moves through a simple descending chord pattern in A minor, played on producer Murray Krugman's Gibson ES-175 through a Music Man amplifier, and engineer Shelly Yakus declared the first take a once-in-a-lifetime groove. The hard part came afterwards: trimming the long solo section took almost as much time as recording it. The released single dropped the slow interlude and reached No. 12 on the Billboard Hot 100 in November 1976, the band's highest American chart placing, and No. 7 in Canada. Rolling Stone named it song of the year. The Guardian later put its charm down to the clash between its gothic theme and its bright, Byrds-like guitar line.
Then came the cowbell legend. In April 2000 Saturday Night Live aired More Cowbell, a six-minute sketch written by Will Ferrell, who played a fictional cowbell player named Gene Frenkle, with Christopher Walken as a producer demanding ever more of the instrument. Dharma said he never tires of it, though he admitted it drained the song's creepiness for a while.
The creepiness has proved resilient. Stephen King, stuck with writer's block on The Stand, drew on the song and quoted it at the start of the novel. It is the only licensed song in the 1978 horror film Halloween, playing as two characters are stalked. Terry Pratchett gave a Discworld family the motto don't fear the reaper in dog Latin, and his own coat of arms later carried a corrected version.
Source: (Don't Fear) The Reaper