Oxford University's Bodleian Library has spent £600,000 to acquire an important manuscript by the composer Mendelssohn.

The famous 17th century library bought the 170-year-old musical score for the Hebrides Overture in auction at Sotheby's.

Funding for the manuscript came from the Heritage Lottery Fund, the Friends of the Bodleian and individual supporters, and its acquisition will stren-gthen the university's position as a leading centre for the study of Mendelssohn's work.

The Hebrides Overture was one of Mendelssohn's major works and was inspired by a trip to Scotland's Western Isles and Fingal's Cave in 1829. It was the first time the score had come up for auction, having been owned by the same family ever since Mendelssohn gave it to a friend in 1837.

The manuscript, which will now be available for detailed study by scholars for the first time, offers an invaluable insight into Mendelssohn's work. It is a working copy and includes the composer's corrections and crossings-out.

The Bodleian already has material relating to the work, including the composer's handwritten arrangement for piano duet and the one drawing he made of the Hebrides. Although Mendelssohn had no real connection with Oxford, the Bodleian has become one of the world's most important archives of his material, including correspondence, albums, diaries, sketchbooks, printed music and books from his library.

The manuscript will be on view in a display from July as part of a series of events marking the 400th anniversary of the library's opening.

Peter Ward Jones, the Bodleian's music librarian, said: "This is a wonderful acquisition for the Bodleian as it celebrates its 400th anniversary. It is a great joy to be able to retain the manuscript in this country, and to unite it with so much related material."