Rapper promises to release a new download every Friday
Rapper says the three will 'make it pop'
Rapper-producer says comedy was behind his decision to sign up to micro-blogging site
Rapper reportedly flew frontman Justin Vernon out to work with him at his Hawaii studio
Rapper also cites Trent Reznor and Radiohead's Thom Yorke as influences
Rapper also visits Twitter's offices for another a cappella performance
Rapper admits feeling 'moments of doubt' in album build-up
'Good Ass Job' is due out on September 14