The 1980 movie “Xanadu” is the prescription for the winter blues with fanciful production numbers that rival the grand studio musicals of the 30s, 40s and 50s. Olivia Newton-John and Gene Kelly headline the cast and are featured in a ballroom song and dance reminiscent of Fred and Ginger. Swing music of Gene Kelly's era mashes up with the disco of the Electric Light Orchestra. John Beck portrays a cartoonist who has a dream of converting an abandoned auditorium into a roller disco emporium and Kelly helps him realize that dream. The reviews were negative for “Xanadu” but I like it.