You may assign, recall, and reassign ePrint music you own as often as needed from the Assign/Recall Music menu. For example, if you have a band set containing eight flute parts, you may assign up to eight flute parts at any given time. But if you have nine flute players in your ensemble, you will need to buy one extra ePrint flute part to satisfy all nine players concurrently.
For choral music, you can only assign as many copies as you own. For example, you will need thirty ePrint choral octavos to satisfy a group of thirty singers. If you add two more singers and need to assign two more choral octavos, you must buy the two additional octavos. Once you have met the minimum purchase quantity for choral octavos, you may buy additional copies as needed from the ePrint Folders screen.