Part of a previously unknown piano concerto by Beethoven will be performed for the first time in Rotterdam.
The Beethoven piece will be played with works by Schubert and Haydn
The 1789 adagio was found as a rough outline in the British Museum then formed into an eight-minute piece.
Dutch pianist Ronald Brautigam will play the piece in a Rotterdam Chamber Orchestra concert on Tuesday.
"As far as we know, Beethoven did write a whole concert that included this adagio and disappeared," said orchestra conductor Conrad van Alphen.
"We have not found any trace that is was ever played before."
The piece was discovered as a rough outline of themes but Dutch musicologist Cees Nieuwenhuizen formed it into an eight-minute adagio.
"It is clearly a piece from his youth but not of a first-timer," said Mr Van Alphen.
"In 1789 Beethoven had already started work on his second piano concerto.
"The atmosphere of this piece is very close to that of the third piano concerto."
The piece will be played alongside works by Schubert, Haydn and Mozart at Rotterdam's De Doelen concert hall.
In 2003 the orchestra performed the Largo movement of Beethoven's Oboe Concerto in F Major, which had been lost for 160 years.