Celebration is evident in the title, the narrative arc and the songs chosen by Umesh Aggarwal for his documentary on AR Rahman. Jai Ho recounts the frequently told journey of the musician who transcended language barriers to become one of the most successful Indian film-music composers of his time. The production features interviews with Rahman, his family members and Indian and Western collaborators, and footage of the phenomenon at his Chennai studio, his Los Angeles home and in concert.

Jai Ho (2015).

Rahman is two years shy of 50 and has been in the limelight since he was 25. He has composed songs across genres for movies in several languages and also produced a clutch of pop albums. Rahman has two Oscars under his belt, Hollywood assignments and musicals to his credit, collaborations with internationally renowned musicians, and advertising endorsements.

He is also at the stage where some of his tunes sound repetitive and seem to have emerged from the innards of a synthesizer rather than a fertile mind. At least that is the way it appears for the followers who were hooked as early as 1992, when Rahman’s tunes for Mani Ratnam’s Roja changed the direction of Tamil film music. Until the mid-2000s, it was possible to pick up a Rahman album and be completely bowled over. Every one of the songs was a hit, and every one of them was a gem. Even his background music was distinctive.

Thee Thee, Thiruda Thiruda (1993).

Rahman is still an in-demand and overworked composer, but his labour produces one or two sticky compositions in a batch of four or five – a strike record that is normal for his peers, but not what we have come to expect from this prodigy. Rahman’s background scores are rarely earworms, and his tendency to sing many of his own tunes is paying poor dividends.

But the tensions and disappointments that characterise Rahman’s current phase are absent from Jai Ho. The 125-minute-long documentary is a celebration of Rahman’s career thus far, with an emphasis on his national and international work aimed at a general audience that will be unfamiliar with the bulk of his early work in South Indian cinema.

There is no context provided for the musical journeys that preceded Rahman, most notably the one charted by South Indian film music composer Illaiyaraja, whose ability to fuse folk tunes with Western-style arrangements in the 1970s and ‘80s prepared the ground for Rahman’s experimentation. Rahman’s sound, which he had tested in television commercials before Mani Ratnam signed him up for Roja, was fresh, unique and different from what had been heard before, but in one sense, the Tamil film soundscape had already shifted because of Illaiyaraja.

Kannalane, Bombay (1995).

Rahman’s achievements very early on include his use of eclectic instruments and unusual arrangements, his appreciation of unconventional voices, and his fearlessness in writing songs that could exist on their own beyond the movie’s narrative. There can be a separate documentary on the remarkable variety of voices found in Rahman’s music, just as there can be another film on how filmmakers, cinematographers and choreographers have been encouraged to shoot differently to set his tunes to images.

Director Mani Ratnam, who has worked exclusively with Rahman since Roja and has been rewarded with some of his most fabulous compositions in such films as Bombay, Thiruda Thiruda, Alaipayuthey, Iruvar and Dil Se, explains what a soundtrack meant Before Rahman. “The rest of the music was heavy, lots of clutter and instrumentation,” Ratnam tells Umesh Aggarwal. But Rahman’s music “in the early stages was sparse, it had a lot of breathing, a lot of air, and a lot of space for it to exist.”

Chinna Chinna Aasai, Roja (1992).

Jai Ho uses Rahman’s game-changing work in Tamil cinema as a base to leap into Rahman’s latter-day national and international fame. Aggarwal, who has previously directed the critically acclaimed documentary Brokering News, about paid editorial and conflict of interest in media ownership, concentrates on Rahman’s Bollywood phase. It began with dubbed versions of his Tamil films, was officially inaugurated with Ram Gopal Verma’s Rangeela in 1995, led to a dream run with such movies as Taal, Swades, Earth, Rang De Basanti, Delhi 6, Jaane Tu… Ya Jaane and continues till this day, although not as fruitfully as before.

Varma, along with Taal director Subhash Ghai, are among the filmmakers in Jai Ho who speak of Rahman’s eccentricities (he works late into the night and rarely delivers a tune on schedule). The documentary goes behind the scenes of the event that launched Rahman’s international career, Andrew Lloyd Webber’s stage musical Bombay Dreams, and Danny Boyle’s Slumdog Millionaire, which earned the composer two Oscars.

Yeh Jo Des Hai Tera, Swades (2004).

Jai Ho is marked by absence, but there is also a great deal present in the documentary to hold attention. Rahman speaks with frankness and without a trace of false modesty of his humble beginnings, his conversion to a Sufi strain of Islam, the influence of his faith on his work, his constant quest for improvement, and the “lack of spontaneity” that has crept in with increased work pressures.

The interviews with other family members and collaborators are equally revealing. Rahman’s mother, a major influence on him, refers to him in the formal third person. Lyricist Gulzar, who has written several of Rahman’s hit tunes, summarises the composer’s contributions with typical wisdom and eloquence.

“First you have the prelude and then the music comes, then you have an interlude, followed by a cross-line,” Gulzar says about the conventional film tune. “From the start, songs were written this way. Rahman broke the pattern… the horizon… at what stage the song will return to the refrain, one never knows…Like classical and semi-classical musicians, he elaborates the tune. These elaborations build links and keep unfolding.”

Rahman’s music comes closest to “blank verse, to a prose poem”, Gulzar says, which has “inspired changes in the content” of film songs.

Ai Hairathe, Guru (2007).

Aggarwal has a lot to pack into 125 minutes, and he does this well. The smoothly narrated documentary is well-timed to tap into the current craze for backgrounders, success stories and biographies of film personalities, especially from Hindi cinema.

Jai Ho’s intended target audience of Rahman’s admirers across continents leads to some fawning interviews and doesn’t allow for a closer look at the smaller but interesting aspects of his career. This bird’s eye view makes him appear more Michael Jackson than a “Mozart from Madras”. Nitpickers might sing a different tune, but for that, they have to blame Rahman’s prodigious and frequently brilliant output in the early years, when he churned out one superb composition after another from a garage that he converted into a recording studio and eventually, a sonic empire.