Orchestra and Opera Greats generously dot the list of guest performers who have played to audiences at the Teatro Colon.  One of the earliest of the legendary tenors was Enrico Caruso, followed by singular appearances of the now famous trio: Placido Domingo, Jose Carreras and Luciano Pavarotti; over the years, guest sopranos ranged from Maria Callas to Renee Fleming. And certainly an illustrious roster of orchestras—the Philharmonic Orchestras from Vienna, Philadelphia, Berlin, as well as the New York and London Symphony Orchestras— has filled the house richly with the sounds of music.  And indeed, ♦  the Teatro Colon is a gorgeous opera house, even more grand inside than out. With its gilded balconies and frescoed ceilings, the theater with a capacity of 2,500 is the second largest of its kind in the world, and it also ranks among one of the top 5 in the world for acoustic quality.  Taking one of its excellent “insider” tours gives visitors deeper understanding of Teatro Colon’s historic role as the leading cultural icon of the city.  But better yet, catch a show, and treat yourself to performances of its resident companies: the Opera House Company, Teatro Colon Ballet and the Buenos Aires Philharmonic Orchestra, which alternates with the Teatro Colon Permanent Orchestra.  ♦  Of note. Que lastima, but most of us probably missed last March’s opening concert of the “Great Performers” series: Gustavo Dudamel (the super-star maestro of the LAPhil—a.k.a. Los Angeles Philharmonic Orchestra) was in town to conduct the Vienna Philharmonic.