She might not have won over the judges hearts on "American Idol" last night but Siobhan Mangus has a much bigger fan; Grammy award R & B singer, Alicia Keys.

Keys mentored the remaining seven contestants on the show and was particularly fond of Irish girl- Cape Cod native, Siobhan.

She gave Siobhan advice on how she could make the Maria Carey/Whitney Houston song "When You Believe" her own.

Keys said about Siobhan, “She’s doing things that I don’t think most people can do.’’ She advised Magnus to milk her higher register, calling it her “money spot.’’

This week's theme was inspirational songs.

Siobhan told host Ryan Seacrest that the song meant a lot to her since she was a child.

When Seacrest asked her, after the judges said it wasn't her best performance, did she realize she was taking on such a tough song, Siobhan responded with "I didn’t want to let the reputations of the original singers scare me off from singing the song, one of my favorites, and one that has touched me very deeply before and the meaning of it is why I’m here right now.’’

Tonight on "Idol Gives Back" Mangus will find out her fate.