Stringed instruments without a finger board, or any similar contrivance which enables the performer to produce a number of different tones on one string, are generally found among nations whose musical accomplishments have emerged from the earliest state of infancy. The strings are twanged with the fingers or with a piece of wood, horn, metal, or any other suitable substance serving as a _plectrum_; or are made to vibrate by being beaten with a hammer, as our dulcimer. Stringed instruments provided with a finger-board on which different tones are producible on one string by the performer shortening it more or less,--as on the guitar and violin,--are met with almost exclusively among nations in a somewhat advanced stage of musical progress. Such as are played with a bow are the least common; they are, however, known to the Chinese, Japanese, Hindus, Persians, Arabs, and a few other nations, besides those of Europe and their descendants in other countries. Wind instruments of the organ kind,--_i.e._, such as are constructed of a number of tubes which can be sounded together by means of a common mouthpiece or some similar contrivance, and upon which therefore chords and combinations of chords, or harmony, can be produced,--are comparatively of rare occurrence. Some interesting specimens of them exist in China, Japan, Laos, and Siam. Besides these various kinds of sound-producing means employed in musical performances, a few others less widely diffused could be pointed out, which are of a construction not represented in any of our well-known European specimens. For instance, some nations have peculiar instruments of friction, which can hardly be classed with our instruments of percussion. Again, there are contrivances in which a number of strings are caused to vibrate by a current of air, much as is the case with the Æolian harp; which might with equal propriety be considered either as stringed instruments or as wind instruments. In short, our usual classification of all the various species into three distinct divisions, viz. _Stringed Instruments_, _Wind Instruments_, and _Instruments of Percussion_, is not tenable if we extend our researches over the whole globe.