Ex-NBA star Daniel Gibson says his music career is BLASTING OFF ... telling TMZ Sports he's been working with some HUGE artists lately, like Chris Brown & Wiz Khalifa.
Gibson put down the rock and picked up the mic some time ago, and when we got him out in L.A., we asked him how things have been going since the career move.
Turns out, Boobie's KILLIN' IT ... telling our guy he's working with some of the hottest artists around, but mostly as a writer because he feels the fact he used to be an NBA star holds his solo career back.
That's a shame ... dude's got some bars, hear 'em below.