Unknown Mozart Piece Found in Leipzig Music Library

An unknown work by Mozart has been discovered in the Leipzig music library. It is believed that the composer wrote it for his sister in the mid to late 1760s, when he was still a teenager. The sheet music was found among the collection of works by German violinist Karl Ferdinand Becker. The serenade is already being performed at the Leipzig Opera. It lasts just over 11 minutes and is intended for a string trio.