Having spent over a decade recording recitals and auditions with my violinst daughter, I’ve developed considerable experience in recording acoustic instruments, particularly piano and string instruments. Typically, I record performances with piano and solo instrument with a minimum of four microphones. In that way, I can adjust the final balance in such a way that the unique features of the venue in which we are recording at optimized. Typically, I record the piano with a pair of small diaphragm condensor mics. The choice of mic for the soloist is very individual and maybe either a condensor-style mic or a ribbon mic. In any session, I may try different mics depending on what I hear. In general, unless the project is very simple, I record through a multi-channel digital mixer, pre-amp and A/D converter directly into my computer. This saves the step of dealing with error-prone portable techniques that use SD cards and the like.
In all cases, I record the video and audio simultaneously, but using separate video and audio equipment. Then once the audio is balanced, I will pair it with the video. I use Logic Pro X on the audio side and Final Cut Pro on the video side.
N.B. You may notice that I mic violins a lot closer than you may be accustomed, often under three feet away from the f- holes. This is important to capture your sound without any muddling that the room may create. I mention this only that you anticipate it; so you’re not intimidated.
Lastly, I just want to say that this may seem over-the-top, and it may be. Audition committees are looking for your musical and technical abilities and to see how you can get around your instrument. Often they will say that the quality need not be excessive. But one never knows how the “mind’s ear” and overall attitude toward you is affected by subtle features such as the fidelity with which your sound is being represented and the air of attention to quality in your recording. I suspect that such “subliminal” effects are significant.