As Rock and Roll Hall of Fame members AC/DC once sang, "It's a long way to the top, if you want to rock & roll" – and that's especially true if you want to join its hall of fame. An artist becomes eligible to join the Rock and Roll Hall of Fame 25 years after the release of his or her debut record. But that alone won't get an act in. To be considered, they must have demonstrated some contribution to the "development and perpetuation of rock & roll." This year, Nirvana join a list of artists that includes Led Zeppelin, Neil Young and Elton John, among others, who were inducted in the first year of elibibility. Other artists wait years and years for inclusion, like Kiss who waited 15 before getting the nod this year. Here's a look at 20 artists who will become eligible for induction over the next five years, why they might make it in and whether or not their induction will be a smooth process.