Even with the machine-gun pace of the release schedule of his ’60s and ’70s heyday, James Brown left a lot of great music in the studio vaults. Motherlode skims from the (mostly) unreleased sounds of the era, adding a discful of indelible funk to the canon. Sometimes rough (the polyrhythmic throwdown “She’s the One” could’ve been a hit single had Brown gone back to recut his vocal), sometimes fully realized (the extended take of “People Get Up and Drive Your Funky Soul” from the blaxploitation soundtrack Slaughter’s Big Rip-off), these tracks earn adjectives like “commanding” as surely as the better-known classics. Working through alternate arrangements (“You Got to Have a Mother for Me” sets fire to “Mother Popcorn”) and revisiting oldies (you can hear James almost chuckling at the funkafied doo-wop of “Since You Been Gone,” formerly “Just Won’t Do Right”), Motherlode is revelatory and mighty.