During roughly 1888–91, Nielsen used a little leather-bound sketchbook in which he notated sketches and ideas for his compositions. The earliest complete movement is Gade for piano on the notes G-A-D-E. The movement is not dated, but it may well have been composed under the immediate impression of Niels W. Gade's death in December 1890, which moved Nielsen deeply. See more about this work at The Royal Library