I had to take a few days to consider the implications of The 1985 Chicago Bears joining the tournament. They absolutely qualify and would now enter as the odds-on favorites to win the whole thing, bringing 21 elite, world class musician-athletes to the table. You have to think that the Fridge alone could pick up entire duos or power trios and airplane spin them over his head into submission. Maury Buford's cowbell would, arguably, be the most useful weapon in the entire tourney, which would make this the first time a punter or a cowbell player would be the most valuable player in any group.
Looking for weaknesses, the most obvious is that the Bears wouldn't be able to bring their helmets, as they performed without them. I can see only one other potential weakness: leadership. I'm a fan of Jim McMahon, and the Punky QB seems like the ideal leader for a take-no-prisoners street fight, but I've always been bothered by Steve Fuller's contributions to the Super Bowl Shuffle, where he threatens to step in and replace McMahon, which is way out of line for a back-up QB. If my band had to take on the Bears, I would try to exploit this potential crack in their armor.
Otherwise, the only way I can see the Bears going down is through attrition or maybe if the team gets bored or cocky and starts letting Mike Singletary take on opposing bands by himself. But even then, Singletary might be able to make it through two or three rounds unassisted.
The Polyphonic Spree would definitely get overtaken by any number of smaller, tougher bands. A strong trio would be able to just tear them apart, and any standard four or five person band would destroy them. I just don't see any toughness there, and they have to fight in their robes. I envision the whole Spree falling into a panic as soon as the fight starts, trying to run away and tripping in their robes and the whole thing turning into a bloodbath.
They'd be replaced in the tournament by USA For Africa, which could send almost 40 members into the fight. While other supergroups might not be able to pull it together and work as a cohesive unit, USA For Africa would have solid guidance between each round from Quincy Jones and player/coach Bob Geldoff. And within the group, you have multiple performers who can and have worked together, including the entire Jackson Five, Hall and Oates and the Steve Perry/Kenny Loggins team. You also have a number of people who look like they could have handled themselves in a fight like Huey Lewis, Waylon Jennings, Bette Midler and Bruce Springsteen. Kim Carnes seemed like she could probably throw down, too. There's also the Dan Aykroyd factor, where opposing bands might become confused and assume they were fighting the Blues Brothers.
Negatives for USA For USA For Africa: two blind guys, Lindsey Buckingham.
Shea, I'm intrigued by the Plastic Ono Band suggestion, but I think I need an official line-up headcount. If there's a line-up that includes all of Elephant's Memory and Keith Moon, they would be excellent dark horse contenders. A Jim Keltner line-up would probably do worse than a Moon, Ringo or Alan White backed band. I also wonder, now, whether or not allowing the Chicago Bears and the Plastic Ono Band opens the door to the entire Concert for Bangladesh band. These are dangerous waters.
Another question: does Prince enter with the Revolution or the New Power Generation? My first impulse is NPG, since Rosie Gaines and that huge drummer guy are probably tougher than everybody in The Revolution. New Power Generation would also have the general numbers advantage, since there are some additional singer-dancers.
On the other hand, Wendy & Lisa would be way tougher than Diamond & Pearl. Also, any team preparing to fight the Revolution would plan their strategy around taking out Prince first, but much like Saddam Hussein, Revolution-era Prince always stocked his band with a couple of guys who looked like himself, so he'd be able to hide among his dopplegangers and throw the other bands off. There's also a possibility that Dr. Fink would be able to patch up wounded members of The Revolution between rounds, or at least fix any instruments that had been broken.