Thomas Hampson has cancelled his upcoming performances with the Orquestra Simfònica de Barcelona. The Baritone was originally scheduled to perform Mahler’s “Des Knaben Wunderhorn” on Dec. 16, 17 and 18. Hampson announced the news on Twitter and stated,  “Very disappointed that I must cancel my upcoming concerts in Barcelona. I’m suffering from a viral tracheitis that makes singing impossible.” However, he noted {…}