Which is another argument that Definitive should probably evolve from on/off-tag to popularity-based-tag.
In that case, definitive refers to popular persuasion, and not to merit or artistry beyond that. A good reason not to include popularity based tag. Definitive should be quantifiable in the terms of the field it refers to.
In a singing performance, the person's ability to sing - breathing technique, true ability to pitch, disciplined, emotional connection, understanding the lyric, artistry with the phrasing and language, and most importantly, the ability through this to make the song their own.
There are a handful of singers whose rendition of Hallelujah move me. I've listened to most of them. After appropriate homage to Leonard Cohen for authoring this piece, the performance I call definitive for the above reasons is by a young 17 year old Brazilian girl, singing with English as her second language.
With her flawed pronunciation, she still exhibits a technique and discipline, emotional connection and breathe control that few popular singers ever achieve.
If ever there was an advertisement for the benefit of a having a great singing teacher, Brenda Dos Santos [[displays that here]Brenda dos Santos - Hallelujah