In the solemn phrase of the Commendatore, in 'Don Giovanni,' we have an interesting example of the happy result with which Mozart has carried out ideas emanating from Gluck. In the opera 'Alceste,' by Gluck, the Oracle sings in one tone, while the orchestral accompaniment, including three trombones, changes the harmony in each successive bar, as follows:-- [Music: Le roi doit mou-rir au-jour- -d'hui, si quelqu'autre au trÈ-pas ne se liv-re pour lui.] That Mozart was much impressed with the effect of Gluck's idea may be gathered from the circumstance of his having adopted it in 'Don Giovanni,' and likewise, to some extent, in 'Idomeneo.' The Commendatore in 'Don Giovanni' sings, accompanied by trombones:-- [Music: Di ri-der fi-n-rai pria dell' au-ro-ra Ri-bal-do! au-da-ce! las-cia a'mor-ti la pa-ce!] There can hardly be a greater difference in the styles of two composers than exists in the style of Gluck and that of J. S. Bach. The masterly command of Bach over the combination of different parts according to the rules of counterpoint is just the faculty in which Gluck is deficient. It is on this account especially interesting to observe how Gluck has employed an idea which he apparently borrowed from Bach. The student may ascertain it by carefully comparing the air, 'Je l'implore, et je tremble,' in 'Iphigenia in Tauris,' with J. S. Bach's beautiful gigue in B flat major, commencing:-- [Music] Clementi, a pianoforte composer, who has certainly but little in common with Gluck, has for his B minor Sonata dedicated to Cherubini--perhaps his best work--a theme which may be recognised as that of the dance of the Scythians in 'Iphigenia in Tauris.' Again, Beethoven's style, especially in his later works, is as different from Haydn's as possible; nevertheless we occasionally meet with a phrase in Beethoven's later works which appears to have been suggested by Haydn. For instance, Haydn, in his Symphony in B flat major (No. 2 of Salomon's set) has a playful repetition of a figure of semi-quavers leading to the re-introduction of the theme, thus:-- [Music] In Beethoven's famous E minor Quartet, Op. 59, a similar figure leads to the theme, thus:-- [Music] A more exact comparison of the two passages than the present short notations permit will probably convince the student of the great superiority of Beethoven's conception. He was one of those rare masters who convert into gold whatever they touch. But it is not the object here to give a list of the similarities and adaptations which are traceable in the works of different musical composers. Such a list would fill a volume, even if composers of secondary rank, who are often great borrowers, were ignored. For the present essay a few examples must suffice, especially as others will probably occur to the reflecting reader.