Apple has confirmed it's reached a deal to buy Shazam, the UK-based app that lets people use the microphone on their mobile to identify songs.

No price has been given for the acquisition, but technology news website TechCrunch reported on Friday that a deal could be worth as much as $US400 million ($531.1 million).

However, that's far short of the most recent $1 billion valuation for the privately held company.

Apple said Shazam would be a "natural fit" with its Apple Music streaming service and it would help users discover new songs.

Apple Music has 27 million users and competes against Spotify, which has 60 million users.

Apple said Shazam's team would be joining its company.

In a statement, Apple spokesman Tom Neumayr said Shazam "is used by hundreds of millions of people around the world, across multiple platforms".

"We have exciting plans in store, and we look forward to combining with Shazam upon approval of today's agreement," he said.

According to tech journalist Micah Singleton, writing at The Verge, Shazam can help Apple in a number of ways — not just by improving Apple Music, but also by stopping Shazam from referring its users to Spotify.

"Also, Shazam's music and sound recognition, which is already integrated with Siri, could gain a deeper integration with iOS, much like Google has done with its song recognition feature on the Pixel," he wrote.

Larry Dignan agrees Apple has bought knowledge that goes beyond its music service.

"What Apple really bought with Shazam is a team that's expert at training models, developing algorithms and managing data," he wrote at ZDNet.

"Shazam is about music — for now. However, that same modelling expertise could apply to many other tasks."

Apple did not elaborate on its plans, but the company will not be able to make any major changes to Shazam until it secures regulatory approval.

Shazam is also available on Android-based devices, but Apple did not say whether it would keep the Android version available.

Shazam ended support for a version of its software that runs on Microsoft Windows PCs earlier this year.

ABC/Reuters