(NOTE: Don’t try watching the video, just close your eyes and listen.)

Fans walked out of Whitney Houston‘s concert at London’s O2 arena last night because of her poor performance.

The singer’s Nothing But Love tour has been beset with problems since she came to Europe, and last night she admitted her voice wasn’t in the best condition as she failed to hit high notes and abandoned her song “The Greatest Love of All” halfway through.

After a shaky rendition of her most famous song “I Will Always Love You,” Whitney said of her voice: “She don’t want to come, my soprano friend. Sometimes the old girl sings, but not tonight. I want to do it, but she doesn’t want to. She’s getting a little - temperamental, even.”

Whitney’s backing singers reportedly carried much of the melody in many songs and Whitney appeared out of breath between numbers.

Whitney was earlier forced to cancel a concert in Paris and reschedule three shows in the UK, after she was hospitalized in the French capital with an upper respiratory infection.

Her first show after recovering in Birmingham, England saw her give a shaky performance and was criticized by some fans.

Some people who walked out of last night’s performance - the first of three at the London venue - are calling for a refund.

Concertgoer Sue posted on an internet message board: “What a sad Night. To see someone so talented turn into such a mess. We left early along with hundreds of disappointed fans. Whether refunds are available or not the tour should be brought to an end before others waste their hard earned cash.”

“I went to the concert last night, and it was heartbreaking to watch someone so talented perform like that,” another poster, Dom, wrote. “She obviously could not reach any high notes at all, despite the audience willing her on, and probably would have been better off miming certain parts, just so the audience could actually hear a full rendition of one of her classics.”

Fans have been told to contact the show’s promoters if they are seeking a refund.