The ad, which launched at 8pm tonight, was created by Karmarama and has been in the making for the past two years.
It is the first time that all of the BBC outlets, from BBC Radio 1 and BBC Radio 6 Music to BBC iPlayer and BBC Radio Cornwall, will join forces to promote its music services.
The ad features Kylie, Chris Martin and Dave Grohl singing a reworked version of The Beach Boys’ God Only Knows. The track will be released as a single in aid of BBC Children in Need.
Other artists include The Beach Boys founder and God Only Knows composer Brian Wilson, One Direction, Paloma Faith, Brian May and Jamie Cullum.
Bob Shennan, the director at BBC Music, said: "This is an exciting moment for BBC Music as we launch to a global audience. With the 80-piece BBC Concert Orchestra at its heart and comprising an array of iconic music stars, from a wide range of musical genres, this ‘impossible’ orchestra is a celebration of all the talent, diversity and musical passion found every single day throughout the BBC."
Art direction on the ad was by Morgan Kennedy, Sarah Kane and Melissa Broker. Sam Walker and Joe De Souza were the executive creative directors.
Walker said: "The God Only Knows campaign demonstrates the pulling power of the BBC with world-class talent and the huge diversity of genres that it supports.
"It was unbelievable that so many artists agreed to take part and help us create a campaign that hopefully demonstrates the amazing power of music."