Who is Cameron Mackintosh from Anything Goes and what is their importance?

Cameron Mackintosh was a well-known and well-regarded producer of musicals in both the United Kingdom and the United States. He is cited by Barrowman as having had a profound influence on his life and his career. Mackintosh encouraged Barrowman to embrace the role of the leading man, and he groomed Barrowman to develop the qualities and abilities that were important for the headlining position in a stage production.
Mackintosh was also openly gay. Men like Mackintosh became examples for Barrowman, who developed the strength and courage to become openly gay as well. Barrowman took it a step further by aggressively advocating for organizations and causes which sought to further gay rights and gay awareness.
Cameron Mackintosh cast Barrowman in Miss Saigon and The Fix, among several other productions. Barrowman relayed particular fondness for a getaway vacation he and his partner Scott Gill had with Mackintosh and his partner in a summer home Mackintosh owned that dated from the Middle Ages. Barrowman and Gill, drunk and amorous, had sex in a tree believing that no one could see them. But Mackintosh saw them through a window and could only beam when he was reunited with the young lovers.