I have a deep love of hats of all kinds. Hats do so much to make an outfit that much more stylish and unique - and atop the heads of these rock stars, they become iconic. While I think Tom Petty does it best, these other cats deserve many kudos as well as they have become as well known for what's on their heads as what's in their music.
From top to bottom: Jamiroquai, Esteban, Flava Flav, Tom Petty, Bob Dylan, Slash
Inspiration: ZZ Top with Slash and John Mayer at the House of Blues on Friday night. Plenty of superb head attire.