For the great disadvantage of the ballet is that it breaks up the continuity of the story; the development of the interest of the opera is arrested, and so far as the music is concerned a complete difference in style is often necessary, the result being that the old train of thought and idea is often only to be resumed with difficulty. Hence it happens that, with a growing appreciation for artistic truth in opera, the ballet has fallen into the background, and most operas seen to-day do not include any performance of what is, at best, a somewhat irrelevant interlude. A few attempts, such as that by Wagner in _Tannhäuser_, to introduce a ballet as an integral factor in the _dénouement_, have not been specially successful, nor have they been widely imitated. As a separate form of entertainment, apart from opera, the ballet has had excellent music written for it by Adam, Sullivan, Tchaïkovsky, and others (in Russia it is a very popular amusement); but in England its appearances are now mainly confined to the music-hall, where it is wedded to music of a light and charming character. [Sidenote: =Curiosities=] A few words as to curiosities of opera; these may be grouped under two or three different heads, somewhat as follows:— (1) Curiosities of Construction and Design. (2) Curiosities of Stage Requirements. (3) Curiosities of the Music. [Sidenote: =Curiosities of Construction=] [Sidenote: =Pasticcio=] The old manner of collecting a mass of heterogeneous materials in the way of airs and songs, and of turning them into a kind of opera, is certainly curious. The name “Pasticcio,” or “pie,” is very applicable to this hybrid growth, which, however, has at times attained to great popularity; one of the most famous instances of its kind is _Muzio Scevola_, produced in 1771. his work was in three acts: the first composed by Ariosti, the second by Buononcini, and the third by Handel; the last-named great composer, with an easy manner of doing things which would certainly not pass muster at the present day, also brought out in 1738 an opera almost entirely made up of favourite airs from his other works; an example which Gluck followed a few years later. The day for this kind of thing is fortunately past, and no composer of serious operatic work would revert to a procedure which is more suggestive of the construction of a pantomime. [Sidenote: =Mixed Languages=]