We now see from Beethoven's notebooks that he gradually assembled the most glorious melodies and, to a degree, selected them out of disparate beginnings…The artist who separates less rigorously, liking to rely on his imitative memory, can in some circumstances become a great improviser; but artistic improvisation stands low in relation to artistic thoughts earnestly and laboriously chosen. All great men were great workers, untiring not only in invention but also in rejecting, sifting, reforming, arranging.