In the following selection from the same piece it will be noticed that this sonority is built up by the movement of the accompanying figures which at the same time sprinkle their own mist with sparks. It is like the passage of a faint comet through the sky, leaving a trail of apparently substantial light. And here this drifting light of sound resolves itself into definite harmonies, in the third, fifth, seventh, ninth, fourteenth and fifteenth measures. The substantial harmonies of the passage are very obviously established by the chords in the left hand part; but it is the movement of the right hand that makes them glow and darken as it were. In those measures not mentioned above, this movement seems to weave a mist about these harmonies, which, in the measures we have numbered, clears for an instant and lets the light through. And that the notes in this movement which have such an harmonic clarity may be not so much emphasized as retained is one of the fine points in the playing of Chopin which the unskilled player is likely wholly to miss, and with it the elusive subtlety of Chopin. [Illustration: Music score] The ordinary pianoforte style of running figuration generally is made up of simple arpeggios or scales. Liszt does not often show himself master of more than such. It is only Chopin who envelopes his harmonies in such an exquisitely spun thread of melody. The last measures of the Barcarolle show such a thread of pure gold, woven and twisted as no other composer for the piano has been able to spin. [Illustration: Music score] In such passages as these three we find a movement which entered the pianoforte style as a necessity (to keep harmonies in vibration) metamorphosed into a line of melody which still retains the power to suggest harmonies. It demands the virtuoso but is in no sense virtuoso music. For virtuoso music is a music in listening to which one hardly knows whether it is sound itself or the rapid movement of sound that thrills. Figures have little musical significance in it. Notice how in the music of the two greatest virtuoso composers for the piano, D. Scarlatti and Liszt, a few figures are repeated endlessly with no variation. The necessity of movement has become a luxury, oftenest not truly beautiful, nor of any but a gymnastic worth.