Some of the best examples for illustrating the studies of our great composers are to be found in those compositions which originally formed part of earlier and comparatively inferior works, and which were afterwards incorporated by the composers into their most renowned works. In thus adopting a piece which would otherwise probably have fallen into oblivion, the composer has generally submitted it to a careful revision; and it is instructive to compare the revision with the first conception. Gluck has used in his operas several pieces which he had originally written for earlier works, now but little known. For instance, the famous ballet of the Furies in his 'Orfeo,' is identical with the Finale in his 'Don Juan,' where the rake is hurled into the burning abyss; the overture to 'Armida' belonged originally to his Italian opera, 'Telemacco;' the wild dance of the infernal subjects of Hate, in 'Armida,' is the Allegro of the duel-scene in his 'Don Juan.' As an instance of adoption from a former work wonderfully improved by reconstruction, may be noticed Handel's Sarabande, in his opera 'Almira,' performed the first time at Hamburg in the year 1705:-- [Music] From this Sarabande, Handel, six years later, constructed the beautiful air "Lascia ch'io pianga," in his opera 'Rinaldo,' performed in London in the year 1711:-- [Music: Las-cia ch'io pian-ga mia cru-da sor-te e che so-spi-ri la li-ber-t‡, e che so- -spi-ri, e che so-spi-ri la li-ber-t‡, Las-cia ch'io pian-ga mia cru-da sor-te, e che so-spi-ri la li-ber- t‡. Il duolo in fran-ga que-ste ri-tor-te de miei mar-ti-ri sÛl per pie----t‡ de miei so-spi-ri sÛl per pie-t‡.] Beethoven's third overture to his opera 'Leonora' (later called 'Fidelio') is a reconstruction of the second. A comparison of these two overtures affords an interesting insight into Beethoven's studies. It must be remembered that Beethoven, not satisfied with the first overture, wrote a second, and subsequently a third, and a fourth. The first three, which are in C major, he wrote when the opera was known by the name of 'Leonora;' and the fourth, which is in E major, when the opera was brought anew on the stage in its revised form under the name of 'Fidelio.' The air of Florestan is indicated in Nos. 1, 2, and 3, composed in 1805 and 1806. No. 2 has the distant trumpet-signal, produced on the stage; and in No. 3 this idea is further carried out; but in No. 4, written in 1814, it is dropped.