Next month, two guitars – one by Eric Clapton and one by Kurt Cobain – will be sold at auction with an estimated price of up to two million dollars.

His guitar Eric Claptonnicknamed “Fool” has bright colors and a psychedelic scene depicting a naked angel on a cloud. The rock ‘n’ roll icon first played his 1964 Gibson SG electric guitar on stage while on tour in the US with British rock band Cream, according to Julien’s Auctions, which is organizing the auction.

The Beatles’ George Harrison gave the guitar to Clapton around 1965, and Cream manager Robert Stickwood commissioned Dutch artists Marijke Koger and Simon Posthuma – known collectively as The Fool – to give the instrument a new look.

In addition to its culturally significant psychedelic style, the guitar was musically significant. Clapton used her to perfect his signature sound, known as the “woman tone”.

The guitar of the late Nirvana singer, Kurt Cobain known as “Skystang I“, is a blue for left handed Fender Mustangs. The American musician played electric guitar throughout Nirvana’s ‘In Utero’ tour in 1993 and 1994, including the band’s final concert in March 1994. Cobain committed suicide about a month later.

The auction will take place at the Hard Rock Cafe in Nashville on November 16th – 18th. A portion of the proceeds will go to the mental health initiative Kicking the Stigma.