 <unk> marked <unk> 's fourth collaboration with Torres . The latter was a composer and producer , also receiving background @-@ vocal credit . The musicians first worked together in 2005 , when <unk> released his tenth studio album ( <unk> ) . He stated that he first " tested " Torres by sending him the " <unk> and <unk> tracks " on the album : " <unk> A <unk> Solo " and " <unk> " . Torres then " went all out on the first demo , hiring a full band that included a string orchestra " . In <unk> <unk> <unk> ( 2007 ) , Torres produced the singles " <unk> " and " <unk> " and provided background vocals on the remastered versions of <unk> 's past hits . In <unk> <unk> ( 2008 ) , Torres produced several tracks ; one was the lead single " <unk> <unk> " , considered <unk> 's " biggest hit in years " by Jason <unk> of Allmusic . 
