A piano piece composed in 1940 by Yoritsune Matsudaira. Around that time, he tried to compose Préludes pour piano and wrote some of them, but he was unable to publish it after having difficulties in using both tonality and ancient Japanese modes. Unlike Prélude en Ré, Prélude en Sol is not included in the Tcherepnin Collection. While the former has the indication of Andante cantabile, the latter is accompanied by the indication of leggiermente. Figures with four sixteenth notes are incessantly repeated. The score has no key signatures, but the music proves to be in G major in the end. However, chromaticism is dominant, as is shown by the fact that only the three of the four figures in the first two measures are played on black keys. Meter fluctuates a little before the climax established in the middle of the piece, and a dominant with many accidentals is resolved to the tonic.