Why do rock stars break their guitars after a show?

They generally don’t. The ones that did, did it to seem “extreme”, and/or because they were intoxicated, I think.

I’ve been to countless rock concerts and never has that happened. I’m sure that if it’s done they’re not real guitars but props.

I was at one concert where that happened. It was Black Oak Arkansas in the 70’s. A piece flew off and hit a member of the audience. It just happened to be a girl that went to my same school so I heard the rest of the story. She was taken to the hospital because it sliced her face open. They paid the hospital bill, gave her a guitar that was not smashed and I think she got tickets to any shows near our state. I’m pretty sure the members of the band were high.

Some rock stars did break them. Pete Townshend of The Who was known for it and I believe Jimi Hendrix also did at times. I suspect it was done initially as part of the adrenaline rush of performing and then it just became part of the performance. I believe it was real guitars as well.

The Who started this. Legend is that Pete Townsend had a temper tantrum and beat one of his guitars to bits when his grandmother complained about all the noise he was making during a rehearsal. Later it was the performance art and the sound that smashing a guitar created.

If they do, it’s to make the poor folks in the audience who can’t afford a guitar shit their pants at the wanton destruction.

Townshend envy

Wonder if the insurance paid for a new one…broken while working.
A way to get a NEW fancy guitar free.

in a word: ANGST

Townsend and the rest of the Who did it for show
Keith Moon amped up the explosives in his drum kit.
Hendrix burnt his to outdo the who at the Monterey Pop Festival
Kurt Cobain / Nirvana
I experienced it a few times when seeing Nirvana. I saw an interview once in which Kurt explained it. This isn’t verbatim, but he said that the instrument destruction at the end of Nirvana concerts served two purposes: if they played a great set, it was a distortion-fueled celebration to end it on a high note filled with noise & feedback, but if they played a mediocre set plagued with mistakes and/or sound issues, it was an outlet to take out their frustration and give themselves & their fans something fun to make up for it. However, the destruction sessions became expected by Nirvana fans at the end of their concerts, so toward the end of their career they turned them into a kind of self-parody by spending increasingly longer periods of time destroying their gear in creative and often sardonically humorous ways to satirize and mock the act (such as Dave Grohl throwing his snare drum in the air and Kurt wielding his guitar like a baseball bat and swinging at it, both repeating this for several minutes).