Those charitable chaps in Rascal Flatts are gearing up for the release of 'Changed,' but in the meantime, they spent this past weekend helping to raise nearly $10 million for a charitable cause. That's hardly chump change.

The Flatts performed at the J.W. Marriott Desert Ridge Resort & Spa in Phoenix, Arizona as part of Muhammad Ali’s Celebrity Fight Night XVIII. The trio helped to raise a whopping $9.1 million in funding at the black-tie event, which is held by the Celebrity Fight Night Foundation, a non-profit organization founded in 1994 by Jimmy Walker. The event has raised nearly $80 million in 18 years.

The money that the Flatts helped to raise will be used to benefit the Muhammad Ali Parkinson Center at Barrow Neurological Institute in Phoenix, as well as several other worthy charities, according to Country Music Tattletale.

Each year, dozens of celebrity guests attend the event. Clearly, the organizers are doing something right.

The Flatts are busy men. When not being philanthropists working hard to raise money for charity, they are touring, making new albums -- ‘Changed' drops April 3 -- and are expanding their brand, working on a chain of restaurants.