diddy has said numbers of times he don't make no beats, he just knows what sounds good. he able to do that because he already established that he know how to make hit records when he was A&R. when he got a chance to producer records, he got together of a team of beatmakers/musican to make the music(the beats) and he would use his ear to find tune the records.
there are many way to become a produer
it not just casted ass the nigga who made the beat
the producer is who ever the record company gives that check to
get their song made
you could be a artist/fomer artist you know how reocrds get made
and you want to try your hand in to it
EX.polow da don, justin timberlake
you could be a writer and also a producer
ex.Neyo, toby gad
you could be a musican and be a producer
ex.1500 or nothing,jr rotem
you can be a engineer and be a producer
ex. mike Dean ,ken lewis
or you can be a exective with an ear and be a producer
ex .Diddy,Ron fair, Rick rubin ,Clive Davis