That's a very good question! I'm so glad you asked that! I love it when students really want to know the answer, (without prompting). The question? "What is an audition committee looking for in these excerpts?" Where do we start?
Preparing to compete for a high-paying job obviously requires a lot more attention than just running through a short list of popular excerpts for a class assignment. Call it getting ready for zero mistake tolerance in front of a very discerning audience. When students come to the point of being serious about preparing for job competition, not just getting through it for experience sake, but with the expectation of nailing it, then reality is at the door. It may be that reality is facing up to the fact that another field would be a better and wiser pursuit. Often however, the question says, I think I can do this. Show me what still needs to be polished. I'm ready to work. Let's go for it!
The result is often amazing. The ears begin to open and practicing becomes much more focused. The grid of competing tends to quickly filter out student-like mistakes. Rhythm, intonation, and dynamics begin to become our weapons rather than nagging duties on a dry checklist. We simply must have these skills, and it becomes a welcome challenge to perfect them.
Running the risk of over-simplifying the needs of good audition prep, I will just pass on advice shared by some who have been very successful at this. Before the performing must come the discipline. You need your tuner, your metronome, and your decibel meter. Put them on the stand and obey them. Over ninety percent of your work can be prepared with the diligent use of these devices, especially the first two. They will insist that you perfect those basics of the music. The machines will hone rhythm, dynamics and intonation which are musicians' tools. And what good is a musician without his tools?!