John Stamos is lending his musical talents and performing experience to this year's slate of hopefuls. The actor and musician will be joining the season as a guest mentor!As the race to the championship continues to narrow, the Top 9 will soon be taking a trip to Disney World for a very special Disney Night episode, where they will get some guidance from Stamos, as well as some inspiration from the Magic Kingdom itself.Stamos, of course, has long been a Disney fan.