Sudden-death smackdown

NBC's "The Voice" is adding a guest coach and changing some rules. Coldplay frontman Chris Martin will assist all four of the coaches. Obviously, the contestants and coaches will need extra expertise to contend with the new rule: The remaining contestants will be paired off to perform the same song separately in a sudden-death match, beginning March 31. The stage replaces the knockout round in which two singers offered a song of their choice.

Carell's new 'Priority'

Steve Carell is set to star in the film version of "The Priority List: A Teacher's Final Quest to Discover Life's Greatest Lessons," a 2014 memoir by David Menasche, a Miami high school teacher who was told that he had a few months to live because of brain cancer. So he traveled to see what his former students were doing. Eight years later, Menasche is still alive but not teaching.

Halftime dysfunction

In an arbitration hearing, the NFL is seeking $16.6 million from rapper M.I.A. for flipping the bird during her performance with Madonna at halftime of the 2012 Super Bowl. That's $1.5 million for allegedly breaching her performance contract and tarnishing the NFL's reputation. Now the league is seeking $15.1 million more in "restitution" as the alleged value of public exposure.

The genius of McPhee

"Smash" and "American Idol" alum Katharine McPhee has landed her next TV role. She'll play a waitress who understands geniuses in CBS' "Scorpion." Elyes Gabel stars as an eccentric genius who with his fellow brainiacs forms the last line of defense to save us from diabolical threats.

Flying the Flag

Black Flag hits the road with Mike Vallely, the band's fifth singer in 38 years; it's booked June 15 at the Triple Rock in Minneapolis. … "Saturday Night Live" has announced that its guests will be Anna Kendrick and Pharrell Williams on April 5 and Seth Rogan and Ed Sheeran on April 12.

Jon Bream