It may surprise you to know that as of this writing, The Simpsons are still on the air. It has been on the air longer than most of What Culture's readers have been alive. To give you an idea of how long the Simpsons has been around, I'll state some facts. It has lasted through seven Batman movies, two Persian Gulf Wars, four American Presidents, Monica Lewinsky, and the internet dot-com boom. It was around before cell phones, high speed internet, and Miley Cyrus was even considered as having an option to exist. It outlasted grunge, Robbie Robertson and the Spice Girls' 'Girl Power' relevance. The Simpsons, primarily due to it's longevity has become a cultural historical artifact of sorts, with shows related to current talking points of years past. Most of their current audience base will just as likely never heard of a guest star as have heard of them; that's how old it's become. Yet The Simpsons continues to comment on the changing social aspects in today's world with it's skewered adult-oriented humor through an assortment of great and talented writers that have had to work within the confines of the city of Springfield and it's inhabitants and never-changing ages. South Park immortalized the influence The Simpsons have in adult-themed cartoons in an appropriately-titled show called 'The Simpsons Already Did It' in which a young, abused Butters aka Professor Chaos tries to wreck havoc on South Park through ideas that have already been on The Simpsons. His inability to do something the Simpsons haven't results in him starting to see South Park as Springfield. It's a surreal yet nice tribute to cartoondom's most iconic show. And to still be going at it for 24 years, you have to have a infinite amount of show ideas and early on Simpsons differentiated themselves by making no question that they were aiming for an adult audience. And how better to do that than to go after the biggest musical icons in the business and ask them to appear (as themselves) in cartoon form. From 50 Cent to Ringo Starr (both not on this list) it has grown as such that to be 'Simpsonized' is a bigger testament to your career than buying a star on the Hollywood Walk of Fame. Here are my choices for the top 20 musical acts to achieve the distinction of having visited Springfield.