Image caption Gold's album will not be released as a "definitive" CD or download

Musician Gwilym Gold has released his debut album in a new format that means listeners never hear the same music twice.

Gold developed the system, called Bronze, over two years, with producer Lexxx and scientists from Goldsmiths University in London.

It allows the tracks on Tender Metal to mutate every time they are played.

"We felt it makes the music more engaging, similar to a live performance," Gold told the BBC.

"Every time it's played, it's renewing itself."

The musician, former frontman of indie act Golden Silvers, added: "As a writer, you can listen to the songs a lot more often without them becoming stagnant.

"That's very much the hope for the listener as well."

The seven songs on Tender Metal are, broadly-speaking, moody electronic pop. They do not change radically from one play to the next - you will not suddenly stumble across a thrash metal incarnation, for example.

But Gold says there are "infinite" possibilities. One track auditioned for this story, Flesh Freeze, evolved subtly over several listens.

Verses drifted in and out of view, while synthesizer phrases and drum loops were pulled apart, sustained and reconstructed from one play to the next.

"You could listen to it billions of times and it wouldn't be the same," Gold said.

Future releases

Some sounds were recorded in a conventional studio, while others are generated in real time by the programme, which knows vital information about the tempo, structure and key of each song.

The Bronze app, and therefore Gold's album, is currently only available for Apple formats such as the iPhone and iPad. He said there were no plans to release a "definitive" version of the record as a CD or download.

Gold suggested other artists may use the format in the future. "We're talking to people at the moment about putting more music out later on in the year," he said.

It is the latest example of artists looking for new, interactive ways to present their work as traditional music sales are decline.

Bjork released her Biophilia album as a series of iPad apps last year, while several artists - including Lady Gaga and Coldplay - have released tracks as "rhythm action" games on mobile devices.