The pair have moved in together in Los Angeles to work on new music
Chicago rapper features in the pop star's new promo
The Chicago rapper performed the track at a secret show in his hometown earlier this week
The US hip-hop artist will continue to work with the Mercury Prize winner in Los Angeles
'Good Enough' and 'Back To School Pack' were originally released in 2009
Pop star tweets rapper in the studio, saying 'We are next'
US rapper tackled the Coldplay classic at a US live gig earlier this week