The public launch of YouTube’s subscription streaming service, Music Key,  has been delayed until mid-September.

The announcement comes less than a week after Spotify announced it was adding video functionality to its platform at a press conference in New York.

The Google-owned company broke the news in an email to its Beta testers, which informed them that their closed trial period was being extended until September 15.

That suggests YouTube either still has more aspects of Music Key to test – or even new ones it’s yet to introduce.

“As one of an exclusive group of Music Key beta users, your feedback has helped make it better each day,” said the messgae.

“And to thank you, we’ve got good news! Your free trial is being extended.”

Music Key is expected to offer both free and paid tiers, with paying subscribers getting ad-free songs and music videos, as well as being signed up to Spotify rival Google Play Music.

Music video uploads will require visual element – even if this is a static ‘card’ – in order to receive royalties from Music Key.

The service was previously expected to launch the service this summer. [Music Business Worldwide]