Salman Khan: Mannu
Loud and boisterous, he is the loveable rogue who chases women, drinks heartily and is heavily into debts. He is an absolute devil, who happens to sing like an angel. His only redeeming feature is his absolute belief in his friendship with Arjun. But naive Mannu doesn't know that this friendship will plunge him into morasses of drugs and destruction, where death may be the only way out.
Ajay Devgan: Arjun
Intense and darkly brooding, he is a complex man burdened by guilt, jealously, and the belief that God has abandoned him. But he's also deeply committed to making the dream that has haunted him since childhood into reality. Such is his obsessive compulsion to fulfill his dream that he won't hesitate to manipulate and destroy the one human being who has implicit and total faith in him - his friend Mannu.
Asin Thottumkal : Priya
She's this conservative South Indian girl weaned on Carnatic music and Bharatnatyam, whose heart secretly yearns for hip hop and rock. When she meets Arjun, she's impressed by his intensity and love for music. And then she meets bold, bad Mannu who declares his love or her at first sight. She laughs him off, little realizing that she's going to be the catalyst who will turn dreams into nightmares.
Rannvijay Singh: Zoheb
He is blindly loyal to Arjun and only sees the world through the prism of Arjun's eyes - and so Arjun's joy is his joy, Arjun's pain is his pain, and Arjun's perceived enemy, he makes his own too.
Adithya Roy Kapoor : Wasim
He may be Zoheb's brother. He may be as loyal to Arjun. But he isn't as blind and retained the capacity to tell right from wrong... good from bad...
They were childhood friends. But they had little in common except their family's vague connection with music. While Arjun's life was consumed by a passionate drive to get on stage and realize his grandfather's unfulfilled dream, Mannu had little interest in his music tutor father's instruments and was content with remaining a child at heart with no higher ambition than enjoying the good things in life. But little did they expect music to strengthen their friendship and then test it with catastrophic results...
Arjun diligently pursued his dream, at the risk of running away from an uncle who was his only family in an unfamiliar land and roaming the streets of London before taking shelter in a music shop and priming himself until he's ready to make his foray into the world of music and showmanship.
As Arjun forges a band with Zoheb and Wasim, two brothers who'd duped their relatives in Pakistan to travel to London in pursuit of their musical aspirations, and Priya, a music enthusiast from a conservative South Indian family, far away in Punjab, music becomes a survival tool for Mannu, who takes to playing in wedding bands in his village.
But when he gets Mannu to London and makes him a part of the band, Arjun soon realizes he's created the biggest threat and obstacle to his own ambitions.
For, Mannu, with his inherent musical gift and irreverent style of performing, becomes an instant darling of the crowds. What has taken Arjun years to achieve, Mannu does overnight. It causes Arjun to feel betrayed by the God to whom he'd surrendered everything in return for eminence in music.
Arjun's unbearable pangs of jealously and insecurity only worsen when Mannu also unwittingly woos and wins his secret love, Priya. As he battles his inner demons, Arjun slowly devises a sinister plan to destroy his best friend. Over a three city tour spanning Paris, Rome and Amsterdam, Arjun sends a naive Mannu on a downward hurtling rollercoaster ride of sex and drugs that almost breaks Mannu's spirit and his love life days before a show at Wembley, a venue where Arjun hopes to have his moment of glory. A venue where his grandfather had failed before a crowd of 25,000 people!
But a rude shock awakens Arjun at Wembley at the expense of his band, his friendship and his credibility - a humbling experience that teaches him the true meaning of acceptance in life.