Mario Sereni
Despite his success , Sereni always remained in the shadow of the more charismatic baritones of his time , principally Leonard Warren , Robert Merrill , Ettore Bastianini , Rolando Panerai and 
<triplet> La Scala <subj> Milan <obj> located in the administrative territorial entity <triplet> Teatro Colón <subj> Buenos Aires <obj> located in the administrative territorial entity