Instruct: Classify the given review into positive or negative sentiment.
Query: Vivica Genaux very disappointing

I am listening to this music right now, broadcast on Concert FM (New Zealand). The orchestra is magnificent but I can't understand why Jacobs chose Vivica Genaux. I am finding her vibrato (in "Cara Sposa") very disturbing, particularly unacceptable in a period instrument performance where I expect not to have to put up with the wobbly singing of so many of today's opera singers.