Apple Music, the iPhone maker's attempt to take on music streaming service Spotify, has launched worldwide.

Apple device users can now listen to more than 30 million songs and live radio by updating their software to receive the new app, which has been built into the existing Music app that comes already installed on iPhones and iPads.

It will also enable users to listen to curated playlists based on moods and activities, as well from other music professionals. Apple says its aim is to "revolutionise" the music industry.

The technology giant is looking to compete with the likes of Spotify and Deezer by providing the streaming service free for the first three months, so anyone can try it out before choosing to pay for it.

Spotify recently announced it had reached 20 million paying subscribers, a number Apple will have its sights set on.

The new Beats 1 radio station was anchored by former BBC Radio One DJ Zane Lowe, who got the station off to an unexpected start when his microphone sound level check was live streamed to listeners before his show began.

"Test, test, test, 37 minutes," he could be heard saying after a sound engineer told him he could not hear him properly.

"I'm going to start the disc again", he added at one point, as ambient music played in the background.

Early users of the act were quick to take to social media to discuss the subject, with more than 32,000 tweets in the first hour of launch that used the hashtag Apple Music or mentioned the service.

The new app was criticised publicly by pop sensation Taylor Swift last week, when the Blank Space singer expressed her disappointment that Apple would not pay royalty fees to artists during the initial free trial period.

In the face of support from other artists, the head of iTunes Eddy Cue took to Twitter to confirm the policy had been changed, with Swift then agreeing to add her music to the service.

AC/DC were another later high-profile addition to the service, with Lowe playing one of their tracks in the first hour of his show.