Amy Winehouse's nine-year-old album Back To Black is outselling newer records from Beyonce, Adele and Pitbull, buoyed by critical praise for the documentary about the singer's sudden rise and fall.
Amy (2015) has grossed more than US$11 million (S$15 million) worldwide since its July 3 release, according to Box Office Mojo. The film chronicles the life of the British pop star, whose musical success and struggle with addiction played out in tabloids before she died of alcohol poisoning in 2011 at age 27.
What distinguishes Amy from other rock documentaries is that the film was produced and financed by Universal Music Group as part of a bigger push into movies. Chief executive officer Lucian Grainge wants the world's largest label to gain a greater share of what fans spend on his artists. The company was also behind Montage Of Heck (2015), about Nirvana frontman Kurt Cobain.
"Increasing our presence in film, television and short-form video is critical to our strategy," Mr Grainge said in an e-mail. "These projects can open a whole new world of opportunities for our artists and underscore their massive appeal beyond recorded music. The success of Amy is but one example of this and there will be many more to come."
At a time of shrinking music sales, movies can deliver more than ticket and album purchases. They can enhance a label's catalogue by resurrecting older artists.
Winehouse's Back To Black has returned to the Billboard 200 charts. The film, distributed by A24, opened in Los Angeles, New York and the United Kingdom on July 3 and has expanded since.
Nirvana moved up in April when Montage Of Heck played in theatres and began airing on HBO, as did the Beach Boys after the Brian Wilson film Love & Mercy (2014) opened in June.
The Best Of N.W.A, a compilation of songs by the iconic rap group, has returned to the Billboard charts ahead of Friday's release of the film Straight Outta Compton (2015). Dr Dre, who founded a record label within Universal, also has produced a soundtrack.
Universal Music, which was once part of the same conglomerate as Universal Pictures and is now owned by Paris-based Vivendi SA, is mining an extensive roster of artists and hit songs to make extra dough from ticket sales and home-video rights. Biopics about Johnny Cash and Ray Charles, which each grossed more than US$120 million in theatres, highlight the potential.
Universal's Republic Records, which distributes Taylor Swift's records, said in March it would produce and finance a number of music-oriented films with distributor IM Global. The first is Rollin' Thunder, about a bowling champion inspired by Nelly, one of Republic's artists.
"Every artist walks in with a demo and a script," said Mr Monte Lipman, Republic's CEO. "Now we have a vehicle where we can do this."
So far, competitors are not following Universal Music into the movie business, though two Sony Music artists, Michael Jackson and One Direction, have been the subjects of concert films that rank among the top 10 in box-office sales for the genre.
Music sales have fallen by almost two-thirds since the mid-1990s, according to the International Federation of the Phonographic Industry, which put last year's revenue at US$15 billion. Online piracy and new technologies, from iTunes to YouTube, have led many consumers to expect to enjoy music for free.
New businesses, such as streaming, have not replaced the lost revenue. Universal Music says it released seven of the top 10 albums of last year, including Swift's 1989, Sam Smith's In The Lonely Hour and the soundtrack to the animated film Frozen (2013), and still suffered a 6.7 per cent drop in sales.
In addition to Amy and Montage Of Heck, New York-based Universal Music is producing a Beatles documentary that will be released next year.
"There is an awful lot of energy and money put into building these brands in the past," said Ms Charlotte Walls, CEO of Catalyst Global Media, an entertainment finance company. "Film documentaries allow music labels and estates to be rewarded for that investment beyond the artist's life."