Dear friend,
I have indeed received your gratifying promise, for which I am most grateful to you!
Even before you had written to me, I had already assigned you a particular role in my enterprise which is of the greatest possible importance for the future. I intend to invite you to follow all my rehearsals, just as you did for the 9th Symphony, in order to record and note down all my remarks, however intimate, concerning the interpretation and performance of our work, and in that way to establish a fixed tradition. I hope this is settled! If you also wished to assist me with the purely mechanical musical rehearsals of the individual singers, your help would be more than welcome. I cannot enter into any actual engagements in this respect, and whatever may have reached your notice in the form of newspaper articles is simply empty boasting, which will do the boasters no good.
With every good wish, I remain
Your sincerely devoted
Richard Wagner.
Source: Selected Letters of Richard Wagner, trans. and ed. Stewart Spencer and Barry Millington (W. W. Norton & Company, 1988), No. 415