Baltimore's game of political musical chairs has begun. No sooner did State Sen. American Joe Miedusiewski confirm his candidacy for next year's gubernatorial campaign than City Councilman Perry Sfikas announced that he would run for Mr. Miedusiewski's Senate seat. "I want to get out there early and let folks know that there's a viable candidate who knows firsthand the frustration, the anxiety and the fear that people feel for the future," Mr. Sfikas, a 1st District Democrat, said yesterday. Mr. Sfikas, 38, is a first-term councilman. He also is the first council member to announce his candidacy for the General Assembly. At least three other council members say they are also contemplating a run for the state legislature. Councilman Timothy D. Murphy, a 6th District Democrat, said yesterday that he is considering running for the House of Delegates from District 47A but would not make a decision before the first of the year. Councilman Joseph J. DiBlasi, also a 6th District Democrat, said he was a "likely" candidate for the state Senate from the redrawn 47th District. And Councilman Martin O'Malley, a 3rd District Democrat, said he was interested in the 43rd District Senate seat he narrowly lost to Sen. John A. Pica Jr. in 1990. Council members would not have to give up their seats to run for the General Assembly because the current council terms do not expire until 1995. In running for Mr. Miedusiewski's Senate seat from the 46th District in South Baltimore, Mr. Sfikas faces a likely challenge from Del. Cornell N. Dypski, who said yesterday he was "absolutely" interested in a Senate race but stopped short of saying he was running. Another potential challenger, Del. Anthony M. DiPietro, said that the race was "too far off to make any statements. I want to get through the '94 [General Assembly] session first." During his two years on the council, Mr. Sfikas was the lead sponsor of 1992 legislation to put a five-year moratorium on the construction of new incinerators in the city. He also opposed two proposed but never-enacted increases in the piggyback income tax and last spring consistently supported a nickel cut in the city's property tax rate. Mr. Sfikas spent 14 years on the staff of Maryland Democratic Sen. Barbara Mikulski before being elected to the City Council in 1991. He out-polled veteran incumbents John A. Schaefer and Dominic "Mimi" DiPietro, who were unseated. If elected to the General Assembly, Mr. Sfikas said he would work to foster a "pro-business climate" in the state that would generate new jobs.