Along with creativity, passion and drive, one of the most important elements of any successful band is chemistry. Placing a group of extremely talented musicians together doesn't always produce the desired results. Conversely, there's that moment when the first chord is struck that it becomes apparent that there's magic about to be made. Sometimes the personality behind the instrument can be as important as the sound coming out of it. For lead vocalists and guitarists especially, who're usually at the forefront of a band, success can often be attributed as much, if not more so to charisma and style than talent and ability. When a popular band undergoes a significant lineup change it can be the kiss of death. The disruption of the band's chemistry, losing a vital member of the songwriting process and changing the public image can all be a severe detriment. It's a testament to a band's talent and appeal when they're able to replace an integral member with someone new and keep the train rolling, sometimes even growing in popularity and garnering increased acclaim. Let's take a look at 10 of the most successful rock bands who've faced this challenge and came out of it on the positive side.