When the cares of the world—terrorism, financial market collapse and personal fears and tragedies—weigh one down, the best antidote is a musical! Two such medicines, spoonfuls of sugar, if you will, are currently available, San Diego Repertory Theatre’s “The Princess and the Black-Eyed Pea” through Dec. 21, and La Jolla Playhouse’s “Xanadu” through Dec. 31. Regarding “Xanadu”: Confession is good for the soul, they say, and I must admit I’m one of the few people on the planet that likes the awful 1980 Universal film that starred Australian pop singer Olivia Newton John as the Greek muse Clio and hoofer Gene Kelly in his last screen appearance as real estate tycoon Danny Maguire. Director Christopher Ashley cast those two roles brilliantly at the Playhouse. Fans remember Elizabeth Stanley, who played the ingénue role in “Cry-Baby” earlier this year. Her role in “Xanadu,” performed mostly on roller skates and with a charming, ludicrous Aussie accent, truly is the better vehicle for her comedic and vocal talents. She literally lights up the stage. In the Kelly role as Clio’s long-ago love, Ashley cast seasoned musical comedy artist Larry Marshall, whose dance and vocal charms are captivating. He is truly a joy, and most effective when he and Clio and his younger self (the amazing Julius Thomas III) sing and dance their way though “Whenever You’re Away from Me.” Throughout the show Dan Knechtges’ choreography is eye candy, and David Zinn’s costumes are ever so amusing. The sparkling musical and lyrical score (Jeff Lynne and John Farrar) includes “I’m Alive,” “Have You Never Been Mellow?” and the hit tune you’ll walk out singing, “Xanadu.” In the role of Sonny, a simple Venice Beach surfer dude who dreams of turning Danny’s crumbling, never-used performance hall into a roller disco, Ashley cast the attractive Max von Essen, who does “simple” to a campy T. The lad’s got legs and pipes as well. The charm of these performances is that they are done with utter sincerity. Also outstanding are Joanna Glushak and Sharon Wilkins as Clio’s nemeses, Calliope and Melpomene. My only complaint is that the placement of microphones occasionally obfuscates song lyrics. Talk about camp — Douglas Carter Beane’s Tony-nominated book, a subtle and sweet send-up of film and 1980s society (does anyone else remember a nickel bag?) hits the funnybone, unless you were asleep in the ’80s. If you’re feeling the least bit blue at holiday time, here’s the cure. See it once, see it gazillion times. “Xanadu” continues at 7:30 p.m. Tuesdays and Wednesdays, 8 p.m. Thursdays through Saturdays, 7 p.m. Sundays, with 2 p.m. matinees on selected Saturdays and Sundays, through Dec. 31 at the Mandell Weiss Theatre, La Jolla Playhouse, 2910 La Jolla Village Drive., There is a special New Year’s Eve show as well. For tickets and information, visit www.lajollaplayhouse.org or call (858) 550-1010.