A music score handwritten by Johann Sebastian Bach and owned by a Japanese music college will be put up for sale next month at Christie’s auction house in London. It is expected to fetch as much as $3 million.

Ueno Gakuen in Tokyo’s Taito Ward, the current owner of the manuscript, confirmed Wednesday the musical score, titled “Prelude, Fugue and Allegro for lute or keyboard in E flat major, BWV 998,” will be auctioned on July 13.

The manuscript, believed to have been penned by the legendary composer in the 1740s, is one of only three complete handwritten musical scores by Bach to be put on the market in the last three decades, according to Christie’s website.

The auction house says no more than 10 complete handwritten manuscripts by Bach are thought to survive in private hands.

It also says no Bach manuscript of any kind for a secular or instrumental work has appeared at auction since the present manuscript was sold in 1968.

The decision to let go of the score it has treasured since 1969 was a managerial decision, Ueno Gakuen said in a written statement to The Japan Times.

For more than 50 years, it contributed to the study of Bach in Japan as an extremely valuable piece of material for research, it said.

“It was an agonizing decision for us to sell the handwritten score,” it said. “Even after its owner changes, we truly hope this handwritten score will be used as the world’s treasure for Bach studies and artistic activities in the future.”

Reasons behind the decision to sell it were not immediately available.

Christie’s website says the manuscript is to be “sold to benefit a renowned musical institution.”

According to the website, although there are a few minor holes and splits and limited damage on the score, the overall condition “is robust and the text clear.”

Ueno Gakuen is a private conservatory established in 1958. Among its graduates are visually impaired pianist Nobuyuki Tsujii, who shot to fame after winning the gold medal at the 13th Van Cliburn International Piano Competition in Fort Worth, Texas, in 2009.

In fiscal 2015, a total of 331 students were enrolled at the college, less than its capacity of 464.