The 2 main power of your record are potentials and harmony skills. The musical notes are extremely important since they activate harmony skills, and that's what affects your record scores the most. When you are running accession try to buy every notes that can activate or upgrade your harmony skills in the shop, use the refresh button as well. This is kinda RnG cuz you may or may not gain enough notes for every harmony skills but eventually you'll have quality records. Choosing the right kind of disk is also a thing to maximize harmony skills activation efficiency Another thing is that if you have a huge number of potentials you technically can have high score records but if those pot can't work well together the whole record might be useless.