Differences between rehearsal and performance

Last week I had my first in a series of conducting lessons I'm having with a new teacher. As a thank you for this first lesson, my flatmate and I invited my new teacher round for dinner. Over dinner we started talking about different orchestras and the different experiences he'd had conducting them. He said something interesting which linked into something I'd been thinking about.

Every conductor complains about how professional orchestras have no enthusiasm in rehearsal; they view the music too much as "just another job". He said that this trait was even worse in the French orchestras because of the "job for life" unionisation musicians they have over there. He said, however, that they were always magnificent in performance and always reached another level. This made me think about why it is the performance is so much more exciting than rehearsal.

In some ways, as a conductor I prefer rehearsals; an opportunity to really acheive the detail that you want, but I always prefer listening to live recordings with the odd chord out of tune but a spontaneous and fresh performance. Orchestral players generally say they prefer that too and the audience makes it easier to perform (despite the coughing!). This was very true for me in my conducting lesson. My teacher said to me at one point, "make this a real performance". With only myself, my teacher and two pianists in a small living room for some reason I felt very nervous. Why? I felt for me, that to do a "real performance" in such an intimate setting was very exposed; indeed I even said that it made me feel almost naked.

Again I ask, Why do you feel ok letting go with a large audience than a small group of people? For me the audience provides a reason, almost a conduit, through which I can then acheive a much greater performance than I would if they weren't there. Maybe if we all let go much more easily in rehearsal we'd acheive far greater things, however much more emotionally draining it would be!