Beethoven: Septet; Mozart: Horn Quintet by Berliner Solisten These are essential works: The Septet Op. 20 (introduced to the world at the same concert as Symphony No. 1) was Beethoven's most popular composition during his lifetime. The third movement is particularly famous to this day. In six movements, this unique combination of winds and strings has countless melodies, fast and slow, with Ludwig's usual humorous and sometimes twist on sounds associated with Mozart and Haydn. Mozart's Horn Quintet might surpass his four Horn Concertos as his greatest work for that instrument. At the time he composed it he said it was one of his best compositions.