Had an interesting thought this morning in the wake of Tom's passing. Tom Petty and the Heart Breakers are one of those rare acts that stayed relevant for 4 decades, which is extremely hard to do without evolving with the times and evolving your sound to stay relevant. Bands like the Rolling Stones and the Beatles evolved their sound much over the course of their respected carriers (the Rolling Stones even had Disco influenced album at one point). What's even more interesting about that statement is they didn't evolve or really change their sound all that much throughout those 40 years. They kept the same signature melodic rock sound they always had from the beginning, and it worked for them, they found long term success doing so. I own at least one Tom Petty album from every decade and they're all good.