The busted black Fender Stratocaster has been put back together, but is no longer playable, Kody Frederick of Julien’s Auctions told AFP earlier this month.

It was signed by all three members of the Seattle grunge outfit as they rocketed to global fame.

The auction house said it had expected the instrument to sell for US$60,000 at the event in front of a live audience at the Hard Rock Cafe in New York City.

Instead, it went for US$595,000, Julien’s said in a statement, calling the total “astounding.”

“You can see here the break that took place as he slammed down the guitar, where the neck here kind of connects, as well as down here on the bottom where he slammed the guitar down,” Frederick told AFP earlier in May.

“Kurt Cobain, when he was on stage, when he played, he was a machine. The man was angry, and you could feel that on stage. And you would feel that by the way he would treat his instruments.

“This broken element, in a strange way, from this broken musician, that really defined this rough and tumble era of music.”

Nirvana’s hits, many of which were penned by Cobain, included “Come As You Are,” “Lithium” and the 1991 breakout “Smells Like Teen Spirit” – a track that became anthemic for a generation of alienated teenagers.

Cobain struggled with substance addiction and depression, and had a tumultuous relationship with his wife, Courtney Love.

He took his own life in April 1994.

The three-day auction, which concludes Sunday, also includes memorabilia from the careers of Eddie Van Halen, Elvis Presley, Freddie Mercury, Bill Wyman and Janet Jackson.