It was very useful however there were minor corrections that needed to be made and sometimes notation for the hi hat wasn't clear about how open it should be. these werent very common though. I did use it often and have learned many songs from it. It wouldnt be useful for someone who cannot read drum notation and doesnt plan on learning how to, but if youre looking into buying this i would imagine that you are already able to. good variety of songs in different genres, two system of a down songs (aerials and toxicity) , rage against the machine, radiohead, smashing pumpkins and queens of the stone age to name some of my favourites. also very helpful for drum lessons, easy to bring with you and drum teachers only seem delgihted to not have to photocopy or notate songs themselves which also saves on time marginally so you can do that little bit extra in a lesson.