It stars Kamal Haasan, Sundarrajan, Srividya and Jayasudha, while Nagesh and Rajinikanth, in his feature film debut, play supporting roles.

Unlike many contemporaneous Tamil films, it was shot entirely in actual houses for their interiors without building sets, as Balachander wanted to convey a more authentic narration.

Despite exploring the concept of relationships between people with wide age gaps, which challenged Indian social mores, it received critical acclaim and became a commercial success, and a breakthrough for Srividya and Haasan.

Unable to digest her mother's hypocrisy, she runs away from home and meets Mahendran in Bangalore while trying to sell some items.

Impressed by his love for his deceased wife, his longing for his son Prasanna who left him, and his commitment to help her, she expresses a desire to marry him, despite the fact that he is old enough to be her father.

Bhairavi is forced to accept Prasanna's proposal when he ends his revolutionary activities and takes up music for her sake, becoming a mridangam player.

Prasanna is happy that Bhairavi has accepted his proposal, but Pandiyan, her ex-lover and Ranjani's father, turns up to meet her and to apologise.

During Bhairavi's next katcheri, where Prasanna is a mridangam player, she sings "Kelviyin Nayagane, Indha Kelvikku Badhil Edhayya?"

[9][10] Before the film's release, author N. R. Dasan accused Balachander of plagiarising Verum Mann, a story he had written for the magazine Kannadasan.

[16] Balachander was impressed by his appearance: his "fragile" health, "powerful" eyes, "chiselled" face and dark skin and did not view them as negatives.

The script of Apoorva Raagangal had been readied, and Balachander wanted Gaekwad to play a "small but interesting part", which he agreed to.

[5] As Gaekwad, who primarily spoke Kannada and his native Marathi, was only "tangentially familiar" with Tamil,[15] Balachander advised him to learn the language.

[19] Unlike many contemporaneous Tamil films, Apoorva Raagangal was shot entirely in actual houses for interiors without building sets, as Balachander wanted a more authentic narration to be conveyed.

[25] For the character's looks, Rajinikanth sported stubble and wore a loose-fitting suit[13] consisting of a dusty coat, loosely worn tie, untucked shirt and trousers;[26][27] his make-up was done by R.

[28] During the initial stages of principal photography, Rajinikanth found Balachander's directing methods very difficult to follow.

Nagesh, who portrayed the doctor Suri who lives a double life as a drunkard named Hari, observed his difficulty and told him, "Don't get tensed up.

[9] Apoorva Raagangal explores the concept of relationships between couples with a large disparity in their ages, which challenged Indian social mores.

[2][30][31] Although it is based on a Vetala Panchavimshati riddle, it has frequently been compared to the American film 40 Carats (1973), which tells the story of a widow who falls in love with a much younger man.

[36][37] V. Ramji of the Hindu Tamil Thisai believes the scene where Prasanna beats up a man for not standing still when "Jana Gana Mana" (the Indian national anthem) is playing, reflects Balachander's penchant for depicting patriotism.

[39] Anand Kumar RS, of The News Minute, however, says the term which also means "pitch distortion", was used to symbolise Pandiyan making "an entry at the wrong time".

Ramachandran said three things that happen soon after Pandiyan's death prove he is not a villain: the music playing in the background is the type usually played when a sympathetic character dies; Bhairavi erases her kumkuma, like any Indian woman would upon becoming a widow; and Pandiyan is found to be holding a note saying his last wish is to see the raga and tala meet, referring to the proposed joint performance of Bhairavi the singer and Prasanna the mridangam player.

As the story revolved around strange relationships, the music director wanted to introduce new ragas to go with the ambient theme.

Despite being released on the same day as Sholay, which went on to become the highest-grossing Indian film at the time, Apoorva Raagangal became a box office success, completing a 100-day theatrical run.

[61] On 22 August 1975, The Hindu said, "K. Balachander has contributed a unique story, dialogues and superb direction in Kala Kendra's [Apoorva Raagangal].

"[62] On 31 August, M. S. Udhayamurthy, writing for the Tamil magazine Ananda Vikatan, appreciated the film overwhelmingly for its quality, calling it one big musical concert happening before his eyes.

[65] In 1976, Apoorva Raagangal was remade by Dasari Narayana Rao in Telugu as Thoorpu Padamara; Srividya and Nagesh reprised their roles.

"[76] The scene where a drunk Suri talks to his own shadow and hurls the empty glass at it while saying "Cheers" led to filmgoers imitating him and throwing cups on the lobby walls in theatres.

"[79] In 2015, Tamil Canadian journalist D. B. S. Jeyaraj wrote, "Though Nagesh has acted in many different roles in Balachander films, one sequence that is perhaps best remembered is the drunkard-doctor of [Apoorva Raagangal].

"[80] Director Mani Ratnam credited Balachander, with Mahendran and C. V. Sridhar, for "weaning the audience away from theatricality", citing a scene in Apoorva Raagangal as an example: "The shadow of the woman upstairs drying her hair falls across the path of the rebellious young man sneaking out of the house.

In Athisaya Piravi (1990), Yama (Vinu Chakravarthy) has to restore Kaalai (Rajinikanth) to life by putting him in the body of a lookalike.