Mendelssohn then set vigorously to work at the music. Miss Dolby, afterwards Madame Sainton-Dolby, made her first appearance at the Leipzig Gewandhaus Concerts, for which she had been engaged by Mendelssohn, on October 25, 1845; and she records the progress of the new oratorio in the following anecdote. "We were dining," she says, "at Dr. Härtel's, and were all seated at the table. The guests included Dr. and Madame Schumann; but Mendelssohn, who was also invited, came late. A vacant place had been left for him by my side. He arrived after the soup had been served, and excused himself by saying he had been very busy with his oratorio; and then turning to me he said, 'I have sketched the bass part, and now for the contralto.' 'Oh!' I exclaimed, 'do tell me what that will be like, because I am specially interested in that part.' 'Never fear,' he answered, 'it will suit you very well, for it is a true woman's part--half an angel, half a devil.' I did not know whether to take that as a compliment, but we had a good laugh over it."[24] [Footnote 24: In case the point of Mendelssohn's joke should be missed by anyone, it must be remembered that the contralto singer in "Elijah" takes the parts of both the Angel and Jezebel, the Queen.] Shortly afterwards Jenny Lind also made her first appearance at the Gewandhaus; and it may here be mentioned that there is every reason to suppose that Mendelssohn wrote the soprano part of his "Elijah" expressly for the "Swedish Nightingale." It is stated in the "Memoir" of Jenny Lind that amongst the beautiful notes of her splendid voice, "the upper F sharp possessed an irresistible charm" for Mendelssohn. He often spoke of it with admiration, and fully remembered that "wonderful F sharp," when he was writing the soprano part of his "Elijah." "He used it with striking effect, as the initial note of the first phrase in 'Hear ye, Israel,' and in many other passages, in which it rings like a trumpet-call throughout the air."[25] This will account for Mendelssohn's having set "Hear ye, Israel," in the keys of B minor and B major--the dominant note of which, and the predominating note of the air, is the said "F sharp." [Footnote 25: "Memoir of Madame Jenny Lind-Goldschmidt." By H. Scott Holland and W.S. Rockstro. London: John Murray (1891). II., p. 243.] Mendelssohn definitely accepted the invitation of the Birmingham Committee in the following letter, which, however, still left the new oratorio an "open question":-- [TO JOSEPH MOORE, ESQ.] [_Written in English._] "LEIPZIG, _December_ 11, 1845.