Save scumming is the process of re-loading an earlier save so you can achieve a desired outcome. In this game, since audition results are randomly generated, you can reload save points to get a different audition roll.
Anyone else who does this? I'll often keep rerolling an audition until I get some sort of outcome I like. I find that this makes an especially large difference in the early game, when having a strong team of high-rarity idols makes your initial business ventures a lot more profitable and reduces the need to spend time practicing.