[...] The visit of the young Bülows was the best thing that happened to me all summer. They stayed in our little house for three weeks - in the very spot that we have prepared for you and Emilie! - I have rarely felt so agreeably and pleasantly stimulated as I was by this intimate visit of theirs. During each morning they had to remain quiet, since I was then busy working on Tristan, of which I read a new act to them each week. For the rest of the day we almost always made music, to which end Frau Wesendonck would faithfully come over to us, so that we had a most appreciative little audience already to hand. Bülow’s mastery of the instrument is quite exceptional; not only his infallible musical intuition, his incredible memory and this amazing dexterity of his, but his indestructibility and constant readiness to play all came in extremely handy.
Once you get to know Cosima, you will no doubt agree with me in thinking the young couple most happily matched: for all their profound understanding and true genius, there is something so carefree and vibrant about these young people that one cannot but feel at ease in their company. It was with great sadness that I finally let them go, but only on the firm understanding that they would return next year. -
[...]
Source: Selected Letters of Richard Wagner, trans. and ed. Stewart Spencer and Barry Millington (W. W. Norton & Company, 1988), No. 202