Lady Gaga has canceled her Montreal show as she battles a medical condition. "Hi everyone. I'm so sorry to share that I'm unable to perform tonight and have to cancel the show," the "Abracadabra" singer, 40, wrote via her Instagram Story on Monday, April 6. "I've been fighting a respiratory infection for the past few days and doing everything I can to rest and recover." Gaga (real name Stefani Germanotta) explained that her illness had "gotten worse," adding that her doctor "strongly advised" that she not perform amid her condition.