`THE POWER GAME,' a four-part television series based on Hedrick Smith's best-selling book, will be presented on public TV Jan. 2-5. It will examine not only Constitution-based powers but also the power of the unelected - the press, lobbies, and governmental staff aides. The programs are produced by Philip Burton Productions and Maryland Public Television. THE BALTIMORE OPERA COMPANY has appointed Michael Harrison, of Opera Columbus, its new general director. During his years with the Ohio organization, the budget grew from $600,000 to $1.7 million and the company came into national prominence with its world premi`ere performance and recording of Thomas Pasatieri's ``Three Sisters.'' LEONARD SLATKIN has been appointed artistic adviser of the Great Woods Institute for the Arts for the 1989 season. In 1990 he will assume the title of artistic director of the institute, in Mansfield, Mass. He will also be principal conductor when the Pittsburgh Symphony is in summer residency at Great Woods. Mr. Slatkin, music director and conductor of the St. Louis Symphony, was music director of the Minnesota Orchestra's Sommerfest. THE OSIPOV BALALAIKA ORCHESTRA from Russia will tour 40 American cities, including a New York appearance at Carnegie Hall Jan. 25. The company, honored as the ``State Russian Folk Orchestra'' since 1945, last toured in the United States in 1977. The current tour begins in Poughkeepsie, N.Y., Jan. 24., and concludes in Oakland, Calif., March 9. AMERICAN PUBLIC RADIO announced that Michael Creedman, a former Wall Street Journal reporter, will serve as anchor of the new business program ``Marketplace.'' The show begins Jan. 2 under the supervision of Pacific Public Radio in Long Beach, Calif., in association with KUSC-FM, Los Angeles. ``Marketplace'' is planned to complement the ``All Things Considered'' newscasts on public radio, with in-depth analysis and a global perspective on business.