from G to G♭; this is called a chromatic semitone and has a less magnitude than the diatonic one.
Finally came the great simplification of music by dividing the octave into twelve equal intervals, each of which was called a mean semitone; thus abolishing practically the difference between the diatonic and the chromatic values. A semitone may now be considered, in practical music, as simply the interval between the sounds given by any two adjoining keys on a well-tuned piano.
The relations between the theoretical magnitudes of the different kinds of semitones are about as follows:—If we represent the magnitude of a mean semitone by 25, the true magnitude of a diatonic semitone will be about 28; of a chromatic semitone about 18; and of the ancient Greek hemitone about 23.
SEMIRAMIDE (i.e. Semiramis, Empress of Nineveh). A favourite subject with Italian writers of operas. Librettos upon it were written by Moniglia, Apostolo Zeno, and Silvani; and Clement's Dictionnaire Lyrique contains a list of 21 operas composed to one or other of these by the masters of the eighteenth century. Voltaire's play on the same subject was also adapted to music and set by Graun (Berlin, 1754), and Catel (1802). Rossini's well-known chef-d'œuvre was written to a libretto by Rossi, and produced at Venice Feb. 3, 1823; and in London, at the King's Theatre, July 15, 1824. In French, as 'Semiramis,' it appeared in Paris July 9, 1860.—Semiramide riconosciuta, words by Metastasio, was set by Vinci, Porpora, Cocchi, Sarti, Traetta, Meyerbeer, and Gluck—the last of these at Vienna in 1748. It is important as revealing some of the qualities by which Gluck has been rendered immortal.
SEMLER, Franz Xaver, a viola-player of some renown in Berlin, the last to use the viola as a solo instrument. He was born in 1772 and lasted down to Feb. 27, 1857. His sister Sophie (afterwards Frau Neilas) in 1784 made a great hit as Constanze in the 'Entfuhrung.' Mozart visited her in 1789 at Potsdam, and her brother tells a charming little story, for which his name is worth preserving. 'Mozart was asked to extemporise, and, as usual, was willing enough. He sat down to the piano, and asked the company for two themes. My sister stood close by to watch his playing. Mozart, always full of his fun, looked up at her and said, "Come, haven't you too got a bit of a subject for me?" (Habens auch a Themerl aufen Gewissen). She hummed one; on which he began in his own charming style, toying first with one and then with the others, and at last bringing in all three together to the delight of everybody.' (Otto Jahn, ii. 411, from Semler's own account.)
SEMPLICE, 'simple'; a direction denoting that the passage so marked is to be performed without any adornment or deviation from the time, used particularly in passages of which the character might possibly be misunderstood. A curious instance occurs in Chopin's Rondo for two pianos, op. 73, where the second subject (in A minor) is inscribed 'Semplice senza ornamenti.' The lovely Arietta which forms the subject of the variations in Beethoven's last PF. Sonata, op. 111, is marked 'Adagio molto sernplice cantabile.'
SEMPRE, 'always'; a word used in conjunction with some other mark of time or expression to signify that such mark is to remain in force until a new direction appears. Its purpose is to remind the performer of the directions which might otherwise be forgotten—as in the scherzo of the Eroica Symphony, where the direction Sempre pp. e staccato is repeated again and again throughout the movement.
SENESINO, Francesco Bernardi detto, i.e. 'F. B. called the Sienese,' one of the most famous of the sopranist singers who flourished in the last century. He was born about 1680, at Siena (whence he derived his name), and received his musical education from Bernacchi, at Bologna. Little or nothing is heard of his career previous to 1719. At that time he was singing at the Court theatre of Saxony, and when Handel came to Dresden in quest of singers, was engaged by him for London.
Senesino's first appearance in this country (Nov. 1720) was in Buononcini's opera 'Astarto,' which at once established him in public favour as a singer of the first rank. He sang next in a revival of Handel's 'Floridante,' and in the celebrated 'Muzio Scævola'; afterwards in Handel's 'Ottone,' 'Flavio,' and 'Giulio Cesare' (1723), 'Tamerlano' (1724), 'Rodelinda' (1725), 'Scipio' and 'Alessandro' (1726), and in various operas and pasticcios by other composers. In 'Giulio Cesare' his declamation of the famous accompanied recitative 'Alma del gran Pompeo' created a special sensation. A writer in the London Magazine (Feb. 1733) relates an amusing anecdote of Senesino in this opera: 'When I was last at the opera of Julius Cæsar, a piece of the machinery tumbled down from the roof of the theatre upon the stage, just as Senesino had chanted forth these words "Cesare non seppe mai che sia timore"—Cæsar never knew fear. The poor hero was so frightened that he trembled, lost his voice, and fell crying. Every tyrant or tyrannical minister is just such a Cæsar as Senesino.' In the opera 'Alessandro' it is said that when, in the part of Alexander, he led his soldiers to the assault of Ossidraca, he so far forgot himself in the heat of combat as to stick his sword into one of the pasteboard stones of the wall of the town, and bear it in triumph before him as he entered the breach! This opera had a run of two months, and its last performance, advertised for June 7, was prevented by the sudden illness of Senesino, who, as soon as he was able to travel, set off for Italy, for the recovery of his health, promising to return the next winter. This promise, however, was not kept in time to enable the Opera-house to open till after Christmas, a fact alluded to in the following prologue, spoken by Mrs. Younger at
