Holst wrote a comic opera "The Perfect Fool" in 1918-22. It begins with a ballet which is danced by Spirits of Earth, Water and Fire. It starts with a wizard (who sounds like Uranus the Magician from Holst´s Planets) who summons the Spirits of the Earth with a trombone. Later, a solo viola calls up the calmer Spirits of the Water. The third section is the dance of the Spirits of Fire. This is the clarinet parts for the orchestral work.