It’s been more than 15 years since grunge-rock pioneer Kurt Cobain took his own life, but the late Nirvana frontman’s legacy appears to be alive and well.

A Sears-model bass guitar owned by Cobain as a teenager sold for $43,750 at a Christie’s auction in New York on Tuesday.

According to the auction house, Cobain used the instrument on two early demo recordings he made at his aunt Mari Earl’s house near Seattle during his pre-Nirvana days.

The demos, one recorded under the moniker Organized Confusion in 1982 and another in 1985 under the name Fecal Matter, are rare to all but the most die-hard Cobain fans.

But one song entitled “Spank Thru” from the 1985 recordings went on to become a staple of Nirvana’s live set and was featured on several of the band’s releases. The tune also became Nirvana’s first official song, according to former Cobain bandmate Krist Novoselic.

The auctioned-off bass is accompanied by a picture of a young Cobain playing the instrument and a letter of authenticity from Mari Earl.

Cobain was catapulted into international stardom after Nirvana’s major-label debut Nevermind became a huge success on mainstream music charts. The department-store bass stands as a humble contrast to the stable of Fender-brand guitars Cobain came to swear by as the frontman for Nirvana.

(Photo: REUTERS/Lee Celano)