Mozart met with constant and unequivocal proofs of esteem on all sides during his visit to Prague; an esteem, too, not of mere fashion or prejudice, but founded on a genuine love of art; he gave himself up unreservedly to the pleasure afforded him by intercourse with his friends and admirers; and many of these retained long after, as Niemet-schek says (p. 93), the memory of the hours passed in his society. He was as artless and confiding as a child, and overflowing with fun and merriment; it was difficult for {SONG FOR MADAME DUSCHEK, 1787.} (135) strangers to realise that they were in the society of the great and admired artist. Mozart had promised his friend, Madame Duschek, that he would compose a new concert air for her; as usual, however, he could not be brought to the point of transcribing it. One day she locked him into a summer-house on the Weinberg, and declared she would not let him out until he had finished the air. He set to work at once, but having completed his task, retorted that if she could not sing the song correctly and well at first sight, he would not give it to her.[25] In truth, the words: "Quest' affanno, questo passo è terribile," in the andante of this song ("Bella mia fiamma," 528 K., part 2) are rendered after a highly characteristic manner; and the intervals for the voice, not easy in themselves, become, by their harmonic disposition, a severe test of pure and correct intonation. Altogether, this is one of the most beautiful of Mozart's concert airs; it makes no great claims on the singer's powers of execution, but it requires a soprano voice of considerable compass and power, and a grand and expressive delivery. It is interesting to observe how this song, animated and energetic as it is in expression, yet differs essentially from the properly dramatic music of "Don Giovanni." Unconnected with any plot, and not designed for the stage, the situation adopts a modified character, the concert singer being in a totally different position from the actor; and the form in which the composer clothes his conception is suitably modified also. On November 15, 1787, immediately after Mozart's return to Vienna, Gluck died; and the success of "Don Giovanni" in Prague may have contributed to induce Joseph II. to retain Mozart in Vienna by appointing him Chamber-Musi-cian (Kammermusikus) on December 7, 1787. For the present, however, there was no prospect of a performance of "Don Giovanni" in Vienna. Salieri had produced his opera of "Tarar" in Paris, in June, 1787, Beaumarchais having spared no pains to create {DON GIOVANNI.} (136)