I suppose this depends on how perfectionism is defined; where the barrier lies. If a perfectionist is concerned only with perfection at release time, then lots

I suppose this depends on how perfectionism is defined; where the barrier lies. If a perfectionist is concerned only with perfection at release time, then lots of imperfect unreleased material can exist. Prince is likely an example of this case. If, on the other hand, perfectionism is applied to every step of the artistic process, then I'd reckon that very few imperfect unreleased materials are likely to exist. Steely Dan are a good example of this case.