For example, a band like Joy Division. Two masterpiece albums in the form of Unknown Pleasures and Closer, and the untimely death of Ian Curtis cut it all short. They were even heading into the direction that New Order eventually went in, and it would have been interesting to see what Ian Curtis would have done if they fully made the leap into electronic music while he was still alive.
But remember, one third of Nirvana in their final incarnation was Dave Grohl. With his talent, image what might have been…