Castor Pollux (2016)
(Concerto for clarinet and orchestra)

Written for clarinetist Mathias Kjøller, Castor Pollux is Pelle Gudmundsen-Holmgreen’s final concerto. The work continues his lifelong interest in the concerto form and follows in the tradition of his solo concertos, beginning with Triptykon for percussion (1995) and spanning concertos for cello, violin, piano, and recorder. His Concerto Grosso (1990) for string quartet and orchestra also played a pivotal role in shaping his approach to the relationship between soloist and ensemble.

The title refers to the mythological twins from Roman mythology, Castor and Pollux—symbols of duality. The concerto was originally intended as one of a pair of twin concertos, though the second was never completed. The idea of mirroring is embedded in the music itself, particularly in the first and third movements, where the strings reflect and reshape shared material.

The clarinet part is both expressive and adventurous, using extended techniques such as multiphonics and singing into the instrument to create interference tones. Percussion has long been a defining element in Gudmundsen-Holmgreen’s music, and Castor Pollux continues this trajectory, using percussive textures as a form-defining force within the concerto. The setup includes tom-toms and oil drums.

The oil drum, in particular, was a favourite instrument of Gudmundsen-Holmgreen’s, notably in Triptykon, where it is described in the score as: “Oil Barrel. Large. Not a steel band drum, but a true oil barrel making a dark sound in the centre. The top must be removed. Should be placed bottom up and raised a little from the floor.”

At the time of the composer’s death in 2016, the work was musically complete but left in fragments due to his distinctive working process. Using all available sketches, annotated drafts, and computer-set materials, composer Anders Brødsgaard edited the score with great care, bringing the work to completion.