Singing is a highly physical skill. An audience (or an audition panel for that matter) will react in awe at a beautifully held high note. Many performers have gotten jobs with that gorgeous high “A.” However, there is danger here.
Just as with any physicality, you may be better able to perform it on some days than others. So you must be sure that you are up to the task; that there’s no fear in your heart (or your eyes); and that it is not likely that you’ll crack. Sometimes singers own sheet music in two or more keys, so they are prepared for various states of vocal ability.
One of the physical tips I like to give singers, is to think of your note as a constant crescendo. You don’t start as loudly as you can go – you build up to it. This makes for a smooth and dramatic vocal performance.
But my main point today is to discuss acting while you’re holding that note. Some singers will get so involved in the physicality of the high note they will forget they are telling a story. The story is the most important part of your singing audition. If it comes to a jarring halt while you are holding a note the concentration of the audience (or panel) is broken. Your eyes, your thoughts, your body, must maintain your story at all times. You should have a feeling, a thought, perhaps a whole sentence in your mind as you sing.
I suggest you make a video of your preparation, so you can see if you’re maintaining your character and your story while you are thrilling us with your glorious sound.