Underwood has remade the Crue song "Home Sweet Home," which will be used as the parting music when a contestant is eliminated.
The song is available as a digital download on iTunes now and on other services on Monday.
Part of the proceeds will be donated to one of Underwood's favorite charities, The Humane Society of the United States.
Underwood says she's always loved that song, and it's fitting both for "American Idol" and for animals finding new homes.
What the El!?! Editorial:
I'm glad they change the songs every year. Can you imagine if we were still having to listen to "and you had a bad day…"