Madonna landed in Israel late Tuesday night, purportedly to perform at the Eurovision Song Contest on Saturday night. While the pop star arrived from London on the private jet of Sylvan Adams, she has yet to sign a contract to appear at the Eurovision in Tel Aviv in just four days.On Monday, Eurovision executive supervisor Jon Ola Sand told media that without a contract, she simply will not be able to perform at the competition. But that doesn't appear to have stopped the singer from arriving in the country. Will she take the stage on Saturday night? That remains to be seen.