I'm Jewish myself, and many Jews of Ashkenazic origin adopted many German surnames. Just like the common Russian surname Sokolov but many Russian Jews have this surname as well. Anyway, we can trace the origin of Bachman in early history can be trace to Bavaria where the name Bachmann with the tribal conflict of the area. They grew alliegence with the princes and nobles, it was told they struggle for power and status in the region of Bavaria. They branch into many houses and their contributions were sought by many leaders in search of powere for the region. That's a early German history of the surname I heard. I probably didn't explain it that good but I know websites and books can :). Now maybe some of are experts on here can give us the true meaning.