Most bands / artists stick around too long (can't really blame them) but also most have an absolute defining peak of their powers. A fair, arguable example would be New Order - Blue Monday, it's the record that defines them and it is practically a signature. Musical peaks do not always sit hand in hand with commercial success though, for example blur - Country House (dreadful) and Madness - House Of Fun (not bad but certainly not their best). Name some musical zeniths..