Alanis Morissette didn't just fill in for Green Day on 'Jimmy Kimmel Live!' last night (Sept. 26), as the pop-punk had to forfeit their booking as a result of frontman Billie Joe Armstrong addressing his substance abuse issues in rehab after last week's dramatic iHeart Radio Festival rant. She also paid homage to the band, performing 'Basket Case,' the same song Armstrong used to launch his expletive-filled tirade about having to shorten his set.

Morissette put her own unique neo-Joni Mitchell spin on the punk anthem, slamming on the breaks, slowing it down and enunciating the words and lyrics in that signature Alanis way.

Remember, she was once a hellion -- "go down on you in a theater" was one of her most memorable early lines -- but she chose not to turn in a wild, hair-flailing performance.

Instead, she was seated and bathed in light. She treated the song as if it were a contemplative ballad. It felt like an intimate, fireside performance. It was subtle and subdued -- and quite moving. In the right hands, even a rager like 'Basket Case' can be given a pretty makeover. It was a refreshing change of pace, and we think Billie Joe would have given the singer a high-five for how she handled his anthem.

As she finished, she even shouted out Armstrong, saying, "We love you, Billie Joe." That got an "awww" out of us -- we won't lie.

Watch Alanis Morissette Cover Green Day's 'Basket Case' on 'Jimmy Kimmel Live!'

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