Carl Nielsen (1865-1931) originally composed Canto Serioso for horn and piano in 1913, later arranging the work for 'cello and piano. The source for this bass clarinet and piano transcription was the original horn version, published in 1944 by Skandinavisk Musikforlag, Copenhagen. After comparison of the different keys chosen by Nielsen for the horn and cello, the F major of the horn version was found to be more suitable to the bass clarinet, and so this original key was maintained.