Jay Z FacebookThe promo video for Jay Z and Justin Timberlake’s ‘Holy Grail’ has got its premiere on Facebook and is available exclusively via the social media site’s video player for its first 24 hours.

“What we’re doing with Jay Z today is really exciting and we think emblematic of the evolution of music and how musicians can connect with their fans,” said Nick Grudin, head of content partnerships for Facebook. Jay Z has 17m Facebook fans while Justin Timberlake has 25m. Timberlake being a backer of the relaunched Myspace clearly had no bearing on the choice of launch platform for the video, although Myspace is also moving heavily into video with its new Music Video Collaborations With Artists We Like initiative (as covered in Wednesday’s bulletin).

This is unquestionably a move by Facebook to steal a march on YouTube, which is the default music video player for most artists and labels. Changing the industry perception for Facebook as a promotional video channel (especially because of pre-existing fans and the ability to cross-promote within Facebook) is one thing, but changing the fan view, especially when ‘YouTube’ and ‘online video’ are synonymous for most of them, is another thing entirely.

Billboard notes that the recent appointment of Jonathan Hull as Facebook’s first head of music partnerships should mean the Jay Z/Timberlake coup is just the start of a much tighter relationship between the social network and musicians.