Studying Pop Stars

Looking at the 100 greatest singers of all time list you can clearly see a lot of them have deceased but still their music continues to sell.
For instance the members of the '27 club' who are known for living fast and dying young have continued to have long lasting careers, way more successful than alive artists who were once popular and now are forgotten about! They music has been adopted by successive generations of fans and their whole persona.
Most pop music is short lived and quickly forgotten about, loosing all meaning overtime; it constantly evolves and changes quickly, however the type of singers seem to stay the same. There are certain qualities that make artists successful, such as youthfulness, rebellion, sexual magnetism, creativity, originality, etc.
However there is a clear pattern among these stars, the longer they remain successful, the more difficult it is to continue this standard, as eventually their originality burns out and fans loose interest. Living fast erodes these stars away and it is very difficult to quit while ahead to maintain the high successful standard, however most dont quit and eventually music moves on and forgets you.
This might be why artists who have died young have been so successful, as they don't become old and unattractive, keeping their musical talent still intact. This also gives an appealing story to fans, with a beginning, middle and an end.