Silent since 1988, Madrid's renowned Teatro Real opera house at last resounded with song this weekend after nine years of renovations. Virtually the whole interior of the 1850-vintage building was redone in the $157-million restoration. Mosaic ceilings were refurbished, and modern lighting, air-conditioning and high-tech stage equipment were added. Opera tickets for the 10-month season are about $14 to $108. To order tickets, call 011-34-558-87-87 or fax 011-34-1-516-06-51.