Canons in notation which any singer could readily understand. Palestrina himself delights in making two Voices sing in Canon, while three or four others carry on the Subject in close Imitation, or complicated Free Fugue; as in the lovely second Agnus Dei of his 'Missa Brevis,' and many others, equally beautiful. In all these cases, the Voices to which the Canon is committed are expected to sing from a single part; but, the Inscription prefixed to that part is so plain, that they find no difficulty whatever in doing so. Thus, 'Symphonizabis' (Missa Brevis as above) indicates a Canon in the Unison. 'Canon in Diapason' or 'Epidiapason,' a Canon in the Octave above, and so on. The sign, 
, or some similar figure—called the Presa—indicates the place at which the second Voice is to begin; and a pause, 
is placed over the note on which it ends. The two Voices can, therefore, sing just as easily from a single part, as from two separate copies.
In modern editions, the matter is still farther simplified, by writing out the Canon in full; though, in the best copies, the Inscription is still carefully retained.
INSTITUT, PRIX DE L', a prize of 20,000 francs founded by Napoleon III. in 1859, in place of the ' Prix triennal ' instituted by the decree of April 1855. By a second decree, of Dec. 22, 1860, it was enacted that from and after 1861 the prize should be biennial, and should be awarded to such work or discovery, of the ten years previous to the award, as should be deemed most honourable or useful to the nation, in the department of each of the five Academies of the Institute successively l'Académie Française, l'Académie des Inscriptions et Belles lettres, des Sciences, des Beaux-Arts, des Sciences morales et politiques. The first prize was adjudged to M. Thiers, as the representative of the Académie Française, in 1861. In 1867 the turn of the Académic des Beaux Arts arrived, and the prize was then awarded to Félicien David, the only musician who has obtained it, the award on the second occasion, 1877, having been made to a sculptor—M. Chapu.
INSTRUMENT (Lat. Instrumentum, Ital. Stromento). In general language, a tool, that by means of which work is done; hence, in music, an apparatus for producing musical sounds. Numerous as are the various kinds of instruments in practical use at the present day, they form but a small proportion of the immense number which have been invented and used from time to time. Out of nearly 340 different kinds mentioned in a list in Koch's Musikalisches Lexicon (art. 'Instrument') only 67 are given as being in use at present, and some even of these are merely varieties of the same genus. Various causes have contributed to the survival of certain instruments and the extinction of others. Quality of tone would of course be a powerfully operating cause, and practicableness in a mechanical sense would be scarcely less so; but besides this, the various ways of combining instruments in performance which prevailed at different periods, had the effect of proving certain of them to be unnecessary, and so indirectly tended to abolish them. Thus before the time of Lully it was customary for the most part to combine instruments of the same class only, and we read of a 'Concert of Violins,' 'Concert of Flutes,' etc.; this fact rendered necessary flutes of deeper compass than are now used, and accordingly we find tenor and bass flutes, extending downwards to F on the fourth line of the bass stave.[1] So soon however as the combination of wind and stringed instruments was found to be preferable, the feeble bass of the flute would be insufficient and unnecessary, and the larger kinds of flutes naturally enough fell into disuse.
All musical sounds are the result of atmospheric vibrations; and such vibrations are excited either directly, by blowing with suitable force and direction into a tube, or indirectly, by agitating an elastic body, such as a stretched string, whereby it is thrown into a state of vibration, and communicates its own vibrations to the surrounding air. One or other of these two is the acting principle of every musical instrument. On tracing the history of the two it does not appear that either is of earlier date than the other; indeed tradition with respect to both carries us back from history into myth and fable, the invention of the earliest form of stringed instrument, the Lyre, being attributed to the god Mercury, who finding the shell of a tortoise cast upon the bank of the Nile, discovered that the filaments of dried skin which were stretched across it produced musical sounds; while the invention of the tibia or pipe—the earliest form of which is said to have been made (as its name implies) from the shank-bone of a crane—is variously ascribed to Pan, Apollo, Orpheus and others.
To attempt to describe, however briefly, all the various kinds of instruments which have been in use from the earliest ages to the present day, would extend this article far beyond its due limits. It will only be possible to mention those which are still of practical importance, referring the reader for a fuller description to the articles under the headings of their various names, and for the earlier and now obsolete kinds to Hawkins's History[2] of Music, which contains copious extracts from the works of Blanchinus, Kircher, Luscinius, and others, illustrated by wood-cuts.
In all essential respects, instruments may be divided into three classes; namely, wind instruments, the descendants of the pipe; stringed instruments, descended from the lyre; and instruments of percussion. This classification, which is of considerable [3]antiquity, is not entirely satisfactory, as there are certain modern instruments which can scarcely be classed under any one of its heads without confusion for instance the Harmonium, which although played by wind, is not strictly a wind-instrument, since
- ↑ In Lully's ballet 'Le triomphe da l'amour,' Paris, 1681, there is a quartet of flutes, the lowest part of which is only possible on a bass flute.
- ↑ Reprinted by Novello and Co. in 2 vols. 8vo. 1868.
- ↑ Casalodorus, writing in the 6th century, gives the same three divisions, uuder the names inflatilia, tensibilia, and percussionalia.
