Apple has confirmed more musicians for its iTunes Festival in London this September, including Elbow, Paolo Nutini and Rudimental.

All will headline their own concerts during the month-long event, with David Gray, The Script, Gregory Porter, Jessie Ware, Ryan Adams and Lenny Kravitz also due to appear.

The artists join previously-announced headliners Kasabian, Pharrell Williams, Kylie Minogue, David Guetta, Beck, Sam Smith and Robert Plant at the festival, with emerging acts SOHN, Jess Glynne and Luke Sital-Singh confirmed for support slots, along with former Busted star Charlie Simpson.

“A couple of years ago we played it for the first time supporting Ed Sheeran and had a lot of fun, so we can’t wait to be back in the Roundhouse headlining,” said Rudimental in a statement.

As in past years, Apple will livestream the concerts through its iTunes software, as well as to iOS devices. The webcasts will be available in more than 100 countries this year.

The festival was first held in London in 2007, with more than 430 artists performing since then. Earlier this year, it also expanded internationally, with a series of gigs in Austin, Texas during the SXSW conference.

The concerts are usually a showcase for Apple’s digital music downloads store, although in 2014, the company has more streaming-music strings to its bow: personal radio service iTunes Radio, and on-demand service Beats Music – the latter acquired along with its parent company Beats Electronics for $3bn earlier in the year.

Neither has launched yet in the UK, but the iTunes Festival could be the ideal launchpad for one or both of them. Apple has long been the dominant player in music download sales, but is now facing more competition from streaming services like Spotify and Deezer.

Apple’s strong relationships with artists – epitomised by the iTunes Festival, but also by regular exclusive deals on new albums – will play a significant role in its response to that competition.

For now, several dates in September remain empty – publicly at least – which will spark speculation about the identity of the acts yet to be confirmed for the festival.

Taylor Swift may be a strong candidate, having announced this week that her new album, 1989, will be released in October, while making it available for pre-order on iTunes.

Swift’s last two albums have also been withheld from streaming services for months after their release – a move guaranteed to put her in Apple’s good books.

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