In 2004, Time Magazine referred to Johnson as a "legendary" acoustician and his design of the acclaimed Esplanade complex—Theatres on the Bay (concert hall plus opera theatre) in Singapore as "one of the best anywhere".
After this time demand arose for concert halls that could serve multiple purposes, hosting symphonies as well as music theater, choral societies and lectures.
Johnson's talents helped make him the go-to person for acoustic design and at time led to his having also worked in collaboration with some of great architects of the world including Cesar Pelli, Jean Nouvel, I.M.
Pei, Moshe Safdie, Barton Myers, Bing Thom, Michael Wilford, Eberhard Zeidler, Fred Lebensold, Sir James Stirling, Robert Venturi, and Rafael Viñoly.
A Memorial service was held in The Allen Room, Frederick P. Rose Hall, Home of Jazz at Lincoln Center, New York City on November 7, 2007.