Modern Chinese music continues the national tradition of following a program, or at least evoking a mood. Cheerful or melancholy impressions of the countryside are frequent. At the same time the musical material used is often borrowed from folk song, or in direct imitation of it. In writing or the violin, many composers have in mind the sound and technique of the two-string Chinese instrument, the erhu. This involves many more glissando than are now customary in Western music, the finger sliding from note to note on a string that has no finger-board to support it. The erhu is, o course, capable of considerable agility, but it relatively limited in range.