At an audition or other anxiety-producing performance, you hope to be so intensely concentrating on creating your mind's aural image of the next few notes or musical gesture that any nervous anxiety about how well things will go, how past notes were played, or the outcome of the audition finds no place in your consciousness. Easier said than done by all of us, but there are ways to work towards this end.

It would be helpful to know which aspects of your playing are most affected by nervousness - intonation, shifting, rhythmic stability, bow control, vibrato, musicianship - in order to give extra attention to supplemental work on these issues. It can sometimes help to focus on a technical issue which gives you confidence; Joseph Silverstein once said that when nervous in performance he would focus his attention on the sensation of the middle finger’s contact with the bow. Hanging on to delivering strong rhythmic control (especially if articulation is involved), listening to how your tone shapes phrases, and immersing yourself in the harmony can all help chase nervousness into the background.

If, despite careful preparation, you have difficulty presenting your best work in the heat of the audition/performance, then perhaps you need to look for ways to simulate the concentration required when "this is the time that really counts." Your practice day should include warm-up, slow work on the passages incorporating all musical details, gradually working passages up to tempo while evaluating how it sounds, much consistent successful repetition up to tempo, and finally a real performance for a recording device of the whole piece up to tempo, without stopping, including all musical details, and without evaluating at the moment how it's going - just aiming to make the next few notes or gesture as you wish them to sound. Knowing that you will have to listen to and evaluate this later should make you concentrate more intensely than in normal practice. But ideally, you should approach all your practicing with “the time that really counts” concentration, even if just isolating a single detail in slow practice tempo.

Listen to that recording; you can make one daily to hear consistency. Evaluate it as if it were someone else and compare it to your aural mental image of the most perfect performance imaginable. Next practice session focus on the things you wish to improve and record again. Keep recreating that aural image away from the viola in your head, and let that continuous train of thought lead you through your recorded "practice performances" of the material. Be aware of and make time for two kinds of practicing - one when you are able to evaluate how things are going, and the other kind in which the aural image of what you are about to play must keep going without any judgmental distraction.

If you can practice spots and perform the whole from memory, it's a great concentration builder. At a professional orchestra audition candidates are not expected to perform from memory, but based on the players I have known, those who regularly perform solo repertoire in concert from memory tend to bring a more intense concentration and more consistent performance to orchestra audition material.