[...]

We are going to publish Martinu’s SINFONIA CONCERTANTE and will try to have the score out for the date of your performance. As you know, we usually print the duration of the music in our scores, and I should like to check our estimate with yours. I suppose the first movement lasts about ten minutes, the second four minutes (or 3-3/4), and the third about ten minutes. This would make the overall duration about 24 minutes. I would be grateful if you would let me have your estimate. I will, of course, ask Martinu, but I am not sure that he can judge this not having heard the work. [...]