No need to be confused. Bloodstone is the old school Kansas City doo wop band turned 70's LA funksters who hit the Top 10 in 1973 with one of the year's great songs "Natural High". They also contributed to one of the last blaxploitation soundtracks for a 1975 movie called Train Ride to Hollywood.
Bloodrock is the Texas hard rock band that hit it big with the 1971 anti-drug death disc "D.O.A."( USA#36) . In 1973, the band released Passages featuring the topical B side "Thank You Daniel Ellsberg" about the military analyst who released classified Pentagon documents to the New York Times in 1971. Ellsberg has publicly supported both Bradley Manning and Edward Snowden for leaking of classified papers .