Lady Silk was a Japanese singer.
She and Imperial Lee gave Ray Morita the crucial missing element for his dimensional travel formula, which was desire. Morita was a fan of Duke Ellington, so he used his formula to travel to a parallel universe where Ellington was able to record his music during the entire 1940s. He took Lady Silk and Imperial Lee with him to that time period on an alternate Earth.
Unknown to Morita, Imperial Lee planned to use the formula to trigger a reaction to destroy that universe. This would cause a ripple effect throughout the multiverse, changing history on other Earths so the Allies would lose World War II. Lady Silk could then return to her home dimension, to a Japanese-controlled Earth. Their plan was foiled by the Seventh Doctor. (PROSE: Atom Bomb Blues)