When recording musicians with real acoustic instruments, I suggest that they bring them over the day before. This is so that the instruments can be acclimatized to the studio live room’s temperature and humidity.
Wood, metal and other materials contract and expand so if you don’t give instruments a chance to settle to a new environment then they may have trouble staying in tune.
Also, for guitar players who aren’t “in the know” they should stretch new strings before putting them on a guitar. Checking intonation BEFORE booking studio time is also a very smart and necessary thing to do.
The same is true for drummers and fresh drum heads. They need to be palm stretched before being tightened onto lugs.
