The title basically is the question. Jellynote offers a big collection of music sheets, tabs, chords and so on for various instruments. However, I didn't anywhere find out wether those are the orignal sheets (either provided, or at least aproved) by the artists, or wether it's just sheets generated and uploaded by the users.
My question especially is targeted towards knowing how accurate the sheets are. The only one who certainly can confirm that the sheets represent the original notes audible is the artist. Everything else may be very plausible guessing, but none the less it remains guessing.