A LIBRARIAN at an evangelical seminary near Philadelphia has made one of the most important musicological finds in memory — because she decided to clean out a dirty cabinet in the building’s basement.

Heather Carbo has unearthed Beethoven’s manuscript score for a piano version of his Grosse Fuge, a work with almost mythical status in the music world. It had been hidden away and forgotten on a bottom shelf at the Palmer Theological Seminary, in the suburbs of the city.

“I was just in a state of shock,” Ms Carbo said.

Sensing the importance of the manuscript, the seminary contacted Jeffrey Kallberg at the University of Pennsylvania, who identified it.

The 80-page manuscript, in Beethoven’s own hand, dates from 1826, the final months of the composer’s life, when he was stone-deaf. It is covered with feverish amendments and deletions in brown and black ink, pencil and red crayon, some so deep that he punctured the paper.

There are smudges where he appears to have wiped away ink while it was still wet and deep erasures where he rubbed through the paper, leaving small holes. In some of the passages, he scribbled the word aus (out).

Stephen Roe, manuscript expert at Sotheby’s, said: “This is an astonishing find. It was known only from a brief description in a catalogue in 1890, but it has never been seen or described by Beethoven scholars. Its discovery will allow a complete reassessment of this extraordinary music.”

It is expected to attract fervent bidding when auctioned by Sotheby’s in London on December 1. The estimated price is £1.5 million, but collectors are likely to ignore the figure.

Scholars are excited because the manuscript offers an insight into the composer’s working methods. In one section, Beethoven inserted fingering markings.

Dr Roe said: “It means he played it. It is touching to imagine the ailing and entirely deaf composer running over pass- ages on the piano, music he could scarcely hear, but certainly feel in his fingers and probably also viscerally.

“The passion and struggle of Beethoven’s working can be seen graphically. The higher and more intense the music, the larger the notes. As Beethoven pushes the music higher than ever written before, the ledger lines are pushed exponentially towards the upper edge of the paper.”

The original version of Grosse Fuge was composed as the finale for the String Quartet in B flat major, Op 130, which Beethoven began in May 1825 and completed in September that year. It has an extraordinarily modern sound and was notoriously difficult for performers and listeners alike when it was first played in 1826.

In the newly discovered score, it was turned into a work for piano four-hands. It is a rare piano transcription by Beethoven of one of his own works.

Dr Roe said that the rediscovery would allow a reassessment of this extraordinary music.

MUSICAL DISCOVERIES

The manuscript for the score of the 1926 hit film The Flag Lieutenant was found this year by a Times’ music critic in a London music shop

Times Recommends

• Henning Mankell: ‘If Wallander was alive, I wouldn’t be a friend of his’
• Secret society's skull and crossbones for sale
• Nigerian leader vanishes after medical treatment