A real gem today - "Alone" by Heart":
The Wilson sisters have got a serious amount of talent, no doubt about it. In Heart, the bulk of the vocal duties are done by Ann Wilson, although Nancy ain't no slouch either. Besides which, Nancy Wilson is a tremenduous songwriter and guitar player. Although not played by Nancy, I've always thought the guitar solo in "Alone" is awesome and a perfect fit (sure; there could've been a few more notes here and there) to the vocal line as well as the theme of the song.
Still; the cornerstone of this song is the vocal performance of Ann Wilson. The sheer impact of her vocals are highlighted each and every time some other singer tries to pull off "Alone" - like in any version of "Idol"