I don't know about you, but hearing people say transcribing the notes of a tune "might" be copyright infringement irritates me profoundly.

If transcribing notes is so illegal, how are songsterr.com, ultimate-guitar.com, and various midi sites surviving (and indeed, profiting off ad money)?

Can we avoid statement like "this may be legally gray area", and instead definitively answer the question on what is illegal and not illegal?