The fire that damaged the venerable Moscow Conservatory has crippled one of the city’s great cultural institutions. “As aspiring performers and composers took final exams last week, there was no electricity, limited telephone service and a trickle of heat from an emergency system. A week after the Dec. 17 blaze, 16 precious concert grand pianos sat damaged or destroyed. Bundles of canvas hoses still dangled from the stairwells, and the air stank of soot.”