...I remember posting this video (espn) the day after it was performed. (3 years ago)
...being a long time fan of Heart as well as Zepplin, I really enjoyed that STH cover at The Kennedy Center because every other band that has tried to cover it has pretty much butchered it.
...But personally I like this version much much better. It was recorded live on an old analog 8 track tape deck in Seattle way back in 1974 and they absolutely nailed it. This was before most people had even heard of Heart and before they had released their debut album. Ann's voice was so incredibly strong back then.
...aside from her obviously powerful 3 octave voice (check out what she does at the 4:55 mark), Ann is also an accomplished flautist which is heard at the intro to the song. Nancy's acoustic guitar is spot on and Roger Fisher's lead guitar solo rocks as well as Jimmy Page's. And the drummer could pass as John Bonham.
(to get the full effect, you gotta turn it up!)