When the green cardigan that Kurt Cobain wore during Nirvana’s 1993 MTV Unplugged concert was sold last year, it went for $334,000, making it the most expensive sweater ever sold at auction. And today, the guitar from MTV Unplugged sold for a record $6 million, making it the most expensive guitar ever sold at auction.

The guitar, a 1959 Martin D-18E with the original hard-shell case decorated by Cobain, was expected to sell for $1-2 million. Bidding reached $1 million before the auction even officially opened, and the winning bid, out of seven total, was $6,010,000. The buyer was RØDE Microphones founder Peter Freedman. The previous record for most expensive guitar a Black Stratocaster owned by Pink Floyd’s David Gilmour, which went for $3.95 million.

For the past few years, the Unplugged guitar has been subject of an extended legal battle between Kurt Cobain’s daughter, Frances Bean Cobain, and her ex-husband Isaiah Silva. Silva refused to give it back after their divorce, claiming that she gave it to him as a gift, while she insisted otherwise. It’s unclear if Silva was behind the auction, as the seller was anonymous.