Kevin Thau, the head of Twitter’s recent #Music app, has left the company – only a week after #Music launched. 

Thau has been accepted as the driving force behind #Music, and was employed by Twitter for years before, focusing on their mobile department. He was also responsible for finding We Are Hunted, the start-up that Twitter bought earlier this year, and whose technology they later used to run #Music.

Thau becomes the third Twitter employee of late to join Jelly, a new start-up created by Twitter co-founder Biz Stone. No one, at this point, seems to know what Jelly is, but according to All Things D, the company has already snapped up Vitor Lourenço and Ben Finkel, both of whom worked for Twitter previously.

After months of talk, Twitter #Music was unveiled last week, as an application that allows users to discover new acts through the musicians that they follow. You can read FACT’s first thoughts on the app here.