<p>Some piano movements are really long, and need to be played multiple times for as close to “perfect” as you want it to be for a very important recording. The problem with a studio session is that it is often very hard to finish in a single session, due to the number of pieces and number of repetitions. It simply gets very tiring for a pianist (or any instrumentalist, for that matter) to play the full repertoire multiple times for schools that require it. Even those that only require two or three pieces for a pre-screening will still want a long sonata movement, for example. </p>
<p>For jazz, a studio session can be a great thing, due to the number of required microphones necessary and set-up space and difficulties. For piano, not so much. Also, we found pianos in recording studios to not always to have the best tone or sound, since recording engineers are not usually pianists.</p>