In place and ready to rehearse. Most of the physical aspects of the preparation are also in place. From here on in, the challenge is going to be focus.
As a piano teacher, I often play simple duets from method books with my students. The first time through can be rough because they have no idea what my part will sound like. I encourage them to keep counting and stick with their part while acknowledging that they have no idea what I will be playing. Multiply this by the number of players in the pit, and that is what the first rehearsal sounds like. And each rehearsal can sound very different as players figure out what to play and when.
If there is a recording available, that can help. However, the conformation of the pit may be very different from a full Broadway orchestra. Most schools and community theatre companies scale back the orchestration to the most important instruments. The piano book may have abbreviated indications of what instruments are playing in certain sections. I needed to remind myself of the meanings for cl, va, vc, and bass cl, then realize that we had no va or vc in the pit. It is common for the keyboard player to pick up missing parts.
Barry Green and W. Timothy Gallwey created an equilateral triangle in "The Inner Game of Music," and I reference this often in teaching. It is called the will-awareness-trust triangle, which I sometimes shorten to WAT. Let's take the will side for granted in this case, just because I'm actually at the keyboard in the pit, and I certainly don't want to mess up. Awareness becomes really wide for me in a pit situation. I need to know where I am in the score, what key I'm playing in (keys often change a lot in musical scores), what cuts have been made, what repeats have been added, what may change in the moment depending on staging, and whether or not I have a brief solo, all of this for starters. And what is happening in the rest of the rhythm section and the pit as well as watching the conductor with a combination of peripheral vision and very fast glances. Concentration is not really the same as inclusive awareness as most folks concentrate by blocking information. In the pit, I need to prioritize lots of information.
And then there is trust. I recently read that the problem with remembering humiliating experiences is that the memory feels like reliving the moment. This may or may not be true for other kinds of memories, but regardless, remembering mistakes is far from helpful in performance. The actual experience of embarrassment may be years in the past or from last night's rehearsal or the last 8 bars, but the moment of recall feels present. If the music is under-rehearsed, it is darn hard to trust what will happen in performance. If the trust issues come from negative self-talk or reliving old failures, the third side of the triangle may collapse.
One night I headed out the door by saying to my husband, "Well, I wonder what I'll mess up tonight?" On my ride to rehearsal, I mentally slapped myself upside the head for doing something I advise against - predicting a poor outcome. After that, I changed my mantra to a message of focus and rolling with the changes. So. Much. Better.
But, as the drummer warned, don't get overconfident. Anything can happen in the pit from night to night. Stay focused and ready to adjust. As one of my experienced pit-playing friends says, "It's always an adventure."