We'd love to know what the budget for this ad was, but it's impressive, nonetheless.

Some of the biggest stars in music - including Beyoncé, Daft Punk, Madonna, Chris Martin, Calvin Harris, Jack White, Rihanna, Kanye West, Nicki Minaj and GOD KNOWS WHO ELSE - have appeared in a new ad for the re-launch of Tidal.

What is Tidal? It's a hi-definition music streaming service (like Spotify, but more pristine) that was recently bought by superstar rapper Jay Z for a reported $56 million - which explains the high-profile ad campaign.

Tidal is being re-launched this evening with a press conference at 5pm ET (10pm GMT) and is expected to announce deals/partnerships with many, if not all of the artists featured on the ad. Tech website techcrunch.com reports that the service might operate in a similar manner to Netflix, by winning exclusive deals to stream album releases ahead of competitors like Spotify and the forthcoming Apple and Beats service.

It's also expected to pay the artists more to stream their albums, which has been a major bone of contention with musicians who feel ripped off by other streaming services. Taylor Swift - an outspoken critic of Spotify - had her catalogue added to Tidal last week, with the exception of her latest album 1989.

You can watch the star-studded ad below - click on the image to play it.