Imtiaz Ali's 'Rockstar' is a decent attempt, that works in most parts. However, the second hour, I felt, was slightly dragging & depressing. Nonetheless, it has a power-packed first-hour, an outstanding performance by Ranbir Kapoor & Wonderful Music by A.R Rahman, working all the way on it's advantage.
'Rockstar' tells the story of how a timid Janardhan Jakhar, transforms into Jordan, a 'Rockstar'. His journey is full of pain, redemption & realizations. In the course of his life, He falls in love with Heer, who plays a major part in his professional/personal life.