[...] Having already spoken with you personally on the subject, I now, as friend to friend, renew my request in writing that you will, in my name, ask the excellent singers, both male and female, known to you in Berlin's esteemed Amateur Society, to assist in as large numbers as possible in my project for a really good performance of Beethoven's Ninth Symphony. I propose to conduct it myself in the old opera-house of Bayreuth on the day of the laying of the foundation-stone for the provisional Festival Theatre on May 22nd this year, if I can be sure of the special co-operation of a picked choir of two hundred men and women and of a hundred instrumentalists selected from among the best members of our foremost orchestras. As the performance is to take place before an audience consisting exclusively of the patrons and other well-wishers of the approaching Festival of Music-Drama in Bayreuth, and accordingly is to serve as a beautiful inauguration ceremony to the latter, I must regard co-operation in it as a free act of sympathy with my enterprise as well as of homage to a great genius, whose blessed patronage I invoke in asking for this sympathy. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 653