A first-edition book of Mozart sheet music, found in a box at an English branch of the charity store Oxfam, is to be sold at Sotheby’s today Wednesday June 8.

A second printing of the first edition of the Sonatas for Keyboard and Violin K10–15, the collection was rescued from a box of donated sheet music at the Oxfam music shop in Reading. The sonatas were composed during the eight-year-old Mozart’s 1764 sojourn in London and were published the following year.

The inscription on the front of the second printing bears a dedication in French to Queen Charlotte, wife of King George III who reigned from 1738 to 1820. The young Mozart had performed in their presence twice during his tour of England as a child prodigy.

The sonatas are being sold by Sotheby’s in its Music and Continental Books & Manuscripts event this week and are expected to fetch £2,000–£3,000. Analysing the paper the music is printed on, the auction house was able to confirm the booklet’s authenticity.

The highlight of the music sale is Mahler’s personal copy of the first edition of his Third Symphony, carrying an estimated price tag of £100,000–£150,000.