Ghost producing 

Ghost producing is most easily defined as the production of instrumentals for an already alleged hip hop producer who needs someone else to make his beats to rap over. Ghost producing is most easily relatable to "Ghost writing." In which a writer writes lyrics for a rapper to spit. Nonetheless this is all usually kept in secrecy unless stated on the albums credits.

"Kanye west bought beats from Madlib, but hes already a producer."

"Yeah, Madlib's ghost producing."

Ghost producing by Kingchop420 June 3, 2012