Some related things to consider are that the level of musicianship in rock is generally better than in earlier times(with more professionalized influences from popular music degrees obtained at institutions like Berklee), the personnel and session playing of top bands has become more changeable & collaborative, including crossover projects, jazz influences(think Cline, Eels, Dirty Projectors, Bonnie Prince Billy, etc.) The power of collaborations really struck me while listening to recent Wilco albums and also the new U2-- an amalgam of U2/Eno/Lanois in which you can pull the fabric apart and clearly recognize the individual contributions of each of these three principals-- and yet an album which unquestionably coheres as U2 and U2 in top form. IMO the older paradigm of a rock band as a monolithic entity is best exemplified by Pearl Jam. No others I can think of-- except perhaps Metallica if you like that kind of stuff.
