Article continues below advertisementLady Gaga's latest tour hit an unexpected pause this week after the singer abruptly canceled her April 6 performance in Montreal, citing a worsening respiratory infection that left her unable to take the stage."I'm so sorry to share that I'm unable to perform tonight and have to cancel the show. I've been fighting a respiratory infection for the past few days and doing everything I can to rest and recover, but it's gotten worse," the 40-year-old pop icon shared in an Instagram Stories post.