start with james brown. lots and lots of james brown. continue listening to james brown until you can spot maceo parker from just a couple notes of a solo, then you can start to think about branching out. lee dorsey, the meters, parliament funkadelic, charles wright and the watts 103rd street rhythm band, sharon jones and the dap kings, etc.
as for the funk brothers, they really didn't play much funk, did they? they were the house band for motown. they mostly played soul/pop/rhythm and blues.