Final answer:
The statement is true; Arthur Brown was known for his theatrical performances and costumes, which aligned with the psychedelic music culture of the 60s and 70s.
Step-by-step explanation:
The statement about Arthur Brown, a heavy LSD user who is a prime example of the British rock side of acid rock, and who often performed in character while wearing costumes, is true. Arthur Brown became well-known for his flamboyant performances, theatrical style, and engaging stage personas, which included outlandish costumes and theatrical makeup. This style of performance was part of the psychedelic music scene during the 1960s and 70s, exemplified by the Woodstock festival atmosphere, where LSD and other psychedelics played a significant cultural role.