About voting for the correct name (part 2):
Ειρήνη Μερκούρη (1,073 plays scrobbled on Last.fm) versus Ειρηνη Μερκουρη (620 plays scrobbled on Last.fm). I prefer the former (with accents on η and υ), because that's her name. By transliterating her name into Eirini Merkouri, the artist remains the same, so I voted for None of the above.
About voting for the correct name (part 1):
Due to incorrect tagging I have scrobbled 318 tracks by Eirini Merkouri, which should be by Ειρήνη Μερκούρη. Of the latter I scrobbled 292 tracks and counting.