Depending on the drive the timeouts can be quite long. Usually far longer than it takes to play a music track. hdparm
can show you the available timeouts for the drive and should show the cureent and recommended values for your drive.
Other than old server drives, the recommendations I have seen are to spin drives down if they have been idle for several minutes. All the drives I have checked in the last few years are pre-configured to spin down when inactive.
You may want to check wether the O/S has spun down the drive when you dismounted it. I believe you can query this with hdparm
. If it isn't spinning down the drive, write a short script to dismount and spin down the drive when you want to stop using it.