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]
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."
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.
"My dear Sir,—Many thanks for your very kind letter. I have now made up my mind to come to Birmingham in August; but I wish to conduct only my own music, as in former years, and have nothing to do with the other parts of the programme. I cannot yet give any promise as to my new oratorio; but in a month or two I shall be able to tell you for certain whether, and when, I can send it. If I cannot, I would try to propose something else of my new music. You want something, whether new or old, for the Friday: would the 'Walpurgisnacht' do for it? I conducted it only once in England, at the last Philharmonic, 1844, and they seemed to like it then. Or would the music to the 'Midsummer Night's Dream' be the thing? My Symphony in A minor, about which you questioned me in one of your former letters, lasts about thirty-five to forty minutes.
"And if you can have Jenny Lind for the Festival, by all means have her, for we have now no singer on the Continent who is to be compared to her. But although she has no fixed engagement, neither at Berlin nor elsewhere, I fear it will be difficult to make her come, as they are all mad about her, and force her into more engagements than she can accept. And Pischek would also be the man, I am sure! But he is known already in England; and if you get Jenny Lind, it will be such a novelty at the same time, and will give a new character to the Festival. Now, before all, I hope that these lines may find you in better health, that your indisposition will be forgotten long before they arrive, and that I may meet you again in perfect strength and happiness.
"Yours very truly,
"Felix Mendelssohn-Bartholdy."