Final answer:
Clowns are the ones known for walking by tapping their head with a brass ball, as part of their comedic and physical humor acts.
Step-by-step explanation:
The people who typically walk by tapping their head with a brass ball are clowns. This sort of behavior is part of a clown's act, which often includes physical comedy and exaggerated movements to entertain an audience. While magicians may use props, they tend to focus on illusions and sleight of hand rather than physical humor. Musicians are usually associated with playing instruments, and jugglers, although they do handle various objects, are known for tossing and catching items rather than tapping themselves on the head.