Duo No. 8 from Mozart's set of 12 Duos for Two Horns, K. 487/496a, performed here on octavin and serpent, in F major rather than the original C major.

Andrew Kershaw shows us a rare and endangered instrument, seldom found in orchestras of today; the serpent - an unusual looking beast, distant relative of the tuba, which composers such as Wagner, Mendelssohn and Berlioz wrote for.