No melody is employed, as in the Western carillon, but rather a complicated polyrhythmical sequence of sounds is produced. "The foundation of Orthodox bell ringing lies not in melody but in rhythm, with its intrinsic dynamic, and in the interaction of the timbres of bells." These sequences have a very special harmony, since Russian bells (unlike Western European ones) are not tuned to a single note. Western bells usually have an octave between the loudest upper tone ("ring") and the loudest lower tone ("hum"). Russian bells have a seventh between these sounds. Generally, a good Russian bell is tuned to produce a whole scale of sounds (up to several dozen of them). This effect is accomplished both by the composition of the alloy from which the bell is cast and the sculpting of the sides of the bell in the mold.