"Nothing Compares 2 u" was written by Prince. It was given for a group he was working with he named "The Family" in the 80's. (More on them on the site soon.) Sinead O'Conner covered the song in early 1990 and released a powerful video to accompany her strong vocals.
Prince won songwriter of the year for 1990 in a Rolling Stone poll for the song. Steven Fargnoli, who managed Prince from the late 70's til 1989 suggested to his new client Sinead to cover the song. The song would catapult Sinead to super-stardom, something that she was not comfortable with.
Prince still performs the song, mostly as a duet. I did hear him sing it solo one time and it was epic. Perhaps the song is too personal for him to perform alone?
There are stories that Prince and Sinead has words about her covering the song that Sinead has verified over the years.
Regardless, here is my grandmother's all-time favorite song and the number 2 video according to an MTV poll, "Nothing Compares 2 U" covered by Sinead O'Conner.-Dr.FB
Diagnosis: Hunt Down The Family's Version. A Pop Classic. St. Paul, Where U At?