Finally there are pages of his music in which the movement of his accompaniment are so free and extended, or so interwoven with what seems the chief idea, that one is at loss to classify them as to style. These it seems to us are the result of his finest art of writing for the piano. In some cases it is easy to speak of the accompaniment as an arabesque, with the implied meaning that, delicately and carefully as it has been shaped and perfected, it remains of secondary importance. So, for instance, with the little prelude in G major, and, to a somewhat greater extent, the study in C minor, opus 10, No. 12. But the prelude in D major is a net of sounds from which nothing but shimmering harmony shines out, though there are two voices for ever entwining about each other. Which is melody and which accompaniment in the prelude in F major? What is going on within the prelude in F-sharp minor, that outwardly seems but a broad melody with whirring accompaniment? At last, in the later works, one comes across accompaniments running from top to bottom of the keyboard, every note of which is but part of a melody. Take as examples of this art the following passages from the fourth scherzo: [Illustration: Music score] These few measures are typical of the essence of the keyboard, rather the pianoforte, style of Chopin, a style showing a grace and flexibility highly characteristic of his music in general. One finds such art only very rarely in the works of other composers since the time of Bach and Couperin, as, for example, in the second Intermezzo in the second number of the _Kreisleriana_ and at the end of Brahms’ Caprice in F-sharp minor, opus 76, No. 1. It is the sort of music which sounds best on the pianoforte, which cannot give the same effect on any other instrument nor by any combination of instruments. There are the constant movement which is necessary to keep the piano vibrating, and the richness of harmony which belongs to no other single instrument except the organ. The homogeneous nature of the scale gives to the runs a continuity of line and of color that is almost uniquely proper to the piano. The single notes of the runs drop with the bell-like quality which likewise belongs only to this instrument. At last it must be noted how the sound of it all floats and changes. This is strikingly a sonority of after-sounds. In the case of the above selection from the Scherzo this is obtained by the arrangement of chords with the broad melody of the left hand. Of the six chords that are struck four are left to vibrate during two measures; that is to say, that five-sixths of their value is given only in after-sounds. Against this tonal background are arranged the rapidly moving notes of the right hand, which a careful study will show accentuates in varying fashion the floating harmonies of the left. So that the whole passage has not only a vague shimmer but a sparkling radiance as well.