Step into the Solar Yoga Center and you get the feeling you're entering a parallel universe. The year is 1971. Yoga — thanks to the Beatles, Mia Farrow and countless hippie disciples — is all the rage in America. The 5th Dimension's "Age of Aquarius" is burning up the charts. And on a quiet, tree-lined street in St. Louis' DeBaliviere neighborhood, a small group of volunteers is forming one of the area's first yoga studios. In a nod to the zeitgeist of the day, they incorporate under the name Universal Great Brotherhood-Aquarian and call their studio Solar Yoga Center. Thirty-six years later the nonprofit yoga center continues to follow the communal mantra of its founders. Instructors volunteer their time; the fees — $10 per class or $40 for a monthlong membership — cover the bills and insurance.