"Rock On" rocks! Critics have given it rave reviews, aficionados are singing its praises. Despite being tagged as a "gap filler" and an average pre-release response at the advance booking counter, Farhan Akhtar's acting-singing debut "Rock On" strikes gold at the box office.

Ramadan is supposed to be a month for average films or "gap fillers" and movies released during this period are not expected to bring big business, according to trade experts. But "Rock On" breaks the mould.

"It is a fabulous film and opened well on the first day. Both critics and the audience liked the film. It has seen 100 percent growth on the second day, " Tusshar Dhingra, COO, Adlabs, told on phone from Mumbai.

"The movie has 'strong legs' as we call in our trade to stay for around the next four weeks. It has a clear run too as there are no other big releases scheduled for the next one month, " he added.

After starting his career with dud directorial debut "Aryan", Abhishek Kapoor has churned out a crowd-pleaser in "Rock On". A thoroughly entertaining film about rock 'n' roll, it has terrific performances from a cast of three newcomers - Farhan Akhtar, Prachi Desai and Nicolette Bird.

Set in Mumbai, the film has an urban feel and revolves around a group of four aspiring musicians who form a hippie rock band called "Magic". It is led by singer Aditya (Farhan) and also has temperamental guitarist Joe Mascarenhas (Arjun Rampal), talented keyboard player Rob (Luke Kenny) and drummer Kedar Zaveri (Purab Kohli).

Farhan is a casting coup as the long haired rock musician - he effortlessly gets under the skin of his character and convincingly portrays the role of an inherently gifted singer.

TV actress Prachi Desai looks perfect in the role of his sophisticated and caring wife who leaves no stone unturned to bring joy and happiness to her husband's mechanical life. She is also instrumental in bringing the four friends together. In short, Prachi makes a successful transition from small to big screen with "Rock On".

However, Arjun is the scene stealer in the film and strikes a chord with audiences as a failed guitarist. Critics have lauded his work.

Commenting upon Arjun's acting in the film, Anupama Chopra, consulting editor, films, NDTV, said: "For me it is the real revelation of Arjun Rampal vis-à-vis others in the film. This is his best role till date. He has really evolved as an actor."

Talented Shahana Goswami matches Arjun's performance in the film. Her dynamic and spontaneous acting as his 'slogging' wife impresses. Luke Kenny, Purab Kohli and Koel Purie too have played their parts with conviction.

"All the actors are so elated to be loved as a group in the film. They are new actors in the industry and nobody is a star son; so it is a great feeling for them, " Kapoor said.

The film has a "Dil Chahta Hai" undercurrent, but Kapoor denies it.

He said: "As a story, screenplay and plot, it has nothing similar to 'Dil Chahta Hai'. However, what can be said to be similar in both the films is that both are progressive in their approach and break from the regular mould and give the same feeling.

"In fact, I'm flattered if people feel the same way because 'Dil Chahta Hai' is a cult classic. I'm totally overwhelmed by the reaction of the audience."

The film, however, lacks universal approach because of its urban shades.

"It's not a pan-India film. It'll connect well with a certain slice of the urban audience and work well in the multiplexes. But for a small town audience, it might not do well because the audience might find it hard to associate with a rock band, " Chopra said.

But the director is not complaining because "Rock On" has been received well in big cities. Following the success of the film, they have bigger plans - the cast of "Rock On" is set to jam in the capital Sep 6.

"I can't wait for the concert in Delhi with live performances from Farhan and Arjun. There is going to be a lot of singing happening, " Kapoor said.

The film's success can be measured from the fact that the September issue of the popular music magazine Rolling Stone features Farhan, Arjun, Luke, Purab and composer trio Shankar-Ehsaan-Loy on the cover page.

The only Indian musician who featured before on the Rolling Stone cover was A.R. Rahman.