Kishio Hirao had a great interest in the instrument called Okuralo (Okraulo) which is invented by Kishichiro Okura in 1930s. Hirao composed many works for Okuralo. One of his masterworks, Sonata for Flute and Piano is originally written for Okuralo and Piano.
The autograph manuscript of Variations on “Kojo no Tsuki” for Okuralo, Flute and Piano was recently discovered by the daughter of the composer, Haruna Hirao. The work is not included in the composition list of Hirao made by his wife. The date of composition is unknown.
– Shota Ezaki (Editor)