A second feature which distinguishes the style of Debussy from that of Liszt is the relative absence in it of the sensationalism of speed. The sort of run we have been discussing, which may be studied in the _Reflets dans l’eau_, or in _Pagodes_, is as rapid as Liszt’s runs. But the monotony of it, the lack of change and therefore of emphasized points, reduces the effect of speed. For speed is chiefly appreciable between definite points. In fact the background of Debussy’s music may be compared to mist, while that of Liszt’s is, we might say, more like a curtain of chain mail. The effect of this prolongation of harmonies by means of the pedal, lightly aided by the fingers, and of this lack of sharp contours is to take from a great part of his music a certain hard substantiality. In other words, recalling what we said of the qualities of sound in the pianoforte in the chapter on Chopin, the sonority of his music is one of after-sounds. Claude Debussy and Maurice Ravel, more than any composers before them, have consciously made use of this peculiar quality of the pianoforte. It is not only their treatment of runs which makes it audible, nor do they depend only upon the after-sounds of notes which have been struck. Holding the dampers off the strings for relatively long spaces allows an almost distinct vibration of overtones or of sympathetic tones to enter into the mass of sound. Both Debussy and Ravel count upon this. The notes they write upon the page are but the starting point of their effects. It is what floats up and away from them that constitutes the background of their music. One finds in the later pieces of Debussy not the old-fashioned indication of the pedal, but such directions as _quittez_, _en laissant vibrer_, or _laissez vibrer_ (let the vibrations continue), which must be intended to attract the ear to after-sounds. He has even invented a notation of such un-substantial sound. Here is an example, from _Les collines d’Anacapri_: [Illustration: Music score] He will fill up a whole measure with notes that find their reason only in the vague sound of the next measure, as here in _La cathédrale engloutie_: [Illustration: Music score] Note also that his spacing of chords, and particularly his strange doubling of parts, brings overtones into prominence. One hears not so much a doubling of parts on the keyboard as an accompanying shadow of sound which is, as it were, cast by them. Witness the choral passages in _La cathédrale engloutie_, and the treatment of chords in _Et la lune descend sur le temple qui fut_. Here, at the beginning, one notices too the inclusion within the chord itself of notes which may properly be considered overtones.