S1·E12 On the Road Again (III)

Hannah Montana isn't the only Stewart family secret! Miley discovers that Robbie was once a pop star in his own right, but just as his career was taking off, he disappeared. Without asking her father if he even wants to make a comeback, Miley gets him a singing gig so that he can get on the road again.

The crossover starts on That's So Raven S04E11 Checkin' Out (I) and The Suite Life of Zack & Cody S02E20 That's So Suite Life of Hannah Montana (II).