Madrid’s Teatro Real is set to present the first-ever performances of Bernd Alois Zimmermann’s “Die Soldaten” in Spain. The occasion will see Spanish conductor Pablo Heras-Casado, the theater’s Principal Guest Conductor, in the pit with a distinguished cast and Calixto Bieto directing. Zimmermann’s only opera is one of the most challenging and extraordinary pieces in the 20th-century and when  Oper {…}