Music fans can be serious people. Ever since Bob Dylan infuriated his folk-loving followers by picking up the electric guitar in 1965 - in some reports narrowly avoiding dismemberment by a hatchet-wielding Pete Seeger - singers and bands often run the risk of alienating their most ardent admirers with every change in artistic direction.
Fans of Metallica have long been considered a special breed, as opening acts in the band's heyday often learned to their own dismay. Counted among those who have had to contend with the heavy metal act's followers is Lou Reed, whose new collaboration with the band, Lulu, has been the subject of much critical debate - and serious derision from devoted Metallica fans.
Reed told USA Today that the band's admirers "are threatening to shoot me" over the concept album, which combines lyrics inspired by a dark German drama with what has been described as anti-melodic metal noise (at least according to Chuck Klosterman).
"They haven't even heard the record yet," the singer explains, "and they're recommending various forms of torture and death."
But while Metallica's fans are commendably serious about their favourite band, they operate in an entirely different league from those of Detroit horrorcore hip hop act Insane Clown Posse. Known as Juggalos, ICP fans have developed a reputation for being, well, insane -- to a degree well beyond such functional members of society as heavy metal aficionados.
From accusations of murder and kidnapping to throwing feces at TV personality Tila Tequila, Juggalos carved out an especially depraved niche for themselves among hardcore music fans, to the degree that the FBI has taken notice, and has counted them as a gang in its 2011 National Gang Threat Assessment - alongside such company as the Hell's Angels, Bloods, Crips and Mexican drug organizations.
Whether this will reduce Juggalo incidents or encourage Insane Clown Posse fans to even more mayhem, it seems clear that Lou Reed has relatively little to fear from a few snippy Metallica listeners.
As for his own fans, Reed isn't particularly worried, telling USA Today "I don't have any fans left. After [1975 album] Metal Machine Music, they all fled. Who cares? I'm essentially in this for the fun of it." Moreover, the singer doesn't feel sufficiently threatened, or concerned by critical backlash, to rule out a second collaboration with Metallica.
"No one wants Lulu Part 2," he said, "but on Radio Lou, in my head where I hear these songs, I want more of it."
And Insane Clown Posse? Well, they are certainly open to collaborations with critically acclaimed artists. After all, the duo not only shared their talents recently with former White Stripe Jack White, but the project combined the group's lyrical stylings with the music of Wolfgang Amadeus Mozart.