Season 2

Actress Nicole Kidman; stand-up comedian Patton Oswalt; The War on Drugs performs.

Actor Liam Neeson; actor Fred Armisen; Carrie Brownstein performs; comedian Simon Amstell.

Actress Lena Dunham; actor J.K. Simmons; rapper Ghostface Killah performs with special music guests rapper AZ and Kool G Rap.

Actor Don Cheadle; actress Kate Bosworth; rapper LeCrae performs

Actor Charlie Day; animal expert Jeff Musial; Darius Rucker performs

Actor Chris Hemsworth; actress Sienna Miller; hip-hop artist Joey Bada$$ performs

Actress Gwyneth Paltrow; actor Josh Gad; Panda Bear performs

Actor Kevin Hart; actor Jay Baruchel; singer-songwriter Meghan Trainor.

Journalist Brian Williams; actress Victoria Justice; technology journalist Joshua Topolsky.

Actress Jennifer Lopez; actor Anthony Mackie; comic Iliza Shlesinger.

Actor Jude Law; actress Keri Russell; Fall Out Boy performs.

Actress Jennifer Aniston; business magnate Bill Gates; chef Mario Batali.

Musician Blake Shelton; journalist Bob Costas; Mötley Crue performs.

TV host Ryan Seacrest; actress Taraji P. Henson; Maddie & Tae perform.

Actor Michael Keaton; musician Gwen Stefani.

Talk-show host Ellen DeGeneres; Neil Young performs; Doc Severinsen sits in with The Roots.

Actor Vin Diesel; actor Carl Reiner; professional basketball player Kobe Bryant; Iggy Azalea and Jennifer Hudson perform.

Actor Will Smith; actress Rosamund Pike; Jack White performs.

Actor Jamie Dornan; Sports Illustrated Swimsuit cover model Hannah Davis; Sheppard performs.

Actress Dakota Johnson; actor Anthony Anderson; Mark Ronson performs.

Actor Hugh Grant; sports analyst Charles Barkley; comic Kyle Kinane.

Actor Colin Firth; actor Jack McBrayer; Triumph, the Insult Comic Dog; The Weeknd performs.

Actor Samuel L. Jackson; actor Norman Reedus; Jessie J. performs with The Roots.

Actor Edward Norton; Craig Robinson; Imagine Dragons performs

Singer-songwriter Taylor Swift; TV host John Oliver; Imagine Dragons perform.

Actress Sigourney Weaver; TV host Andy Cohen; Ella Henderson performs.

Actor Martin Short; actress Ruth Wilson; Walk the Moon performs.

Actor Kevin Bacon; actress Amy Sedaris; Nick Jonas performs.

Singer Christina Aguilera; TV host Jeff Probst; Kid Rock performs.

Actor Josh Duhamel; actress Gabrielle Union; Charlie Wilson performs.

Actor Ice-T; actor Andrew Rannells; Lupe Fiasco performs with The Roots.

Actor James Spader; actress Margot Robbie; musician Tobias Jesso Jr performs

Actor Josh Hutcherson; actresses Abbi Jacobson and Ilana Glazer; chef Michael Schlow.

Actor Ryan Reynolds; actor Terrence Howard; Kelly Clarkson performs.

Actress Judi Dench; actor Ansel Elgort; Gza and Tom Morello perform with The Roots.

Actor Danny DeVito; actress Zoe Kravitz; comic Artie Lange.

Actor Hugh Jackman; actress Tiffani Thiessen; Hozier performs.

Actor Jim Parsons; actor Miles Teller; Wiz Khalifa performs.

Actress Jennifer Garner; actor Eugene Levy; Modest Mouse performs.

Actor Will Ferrell; actress Chelsea Peretti; Boots performs.

Actor Ben Stiller; fashion consultant Tim Gunn; Rixton performs.

Actor Jeremy Piven; singer Ariana Grande; technology journalist Joshua Topolsky; Andy Summers performs with The Roots.

Actress January Jones; professional golfer Bubba Watson; Brandon Flowers performs

Actress Elizabeth Banks; mixed martial artist Ronda Rousey; Little Big Town performs.

Former GOP presidential candidate Mitt Romney; actress Grace Helbig; G Unit performs with The Roots.

Actor Alan Cumming; actress Carey Mulligan; Ludacris performs with The Roots.

Actor Will Forte; musician Adam Horovitz; TV personality Jeremy Wade.

Actress Helen Mirren; actor Oscar Isaac; Wale performs with The Roots.

Actor Ethan Hawke; TV personalities Willie and Korie Robertson; Alt-J performs.

Musician Pharrell; TV producers Roma Downey and Mark Burnett; Milky Chance performs.

First lady Michelle Obama; actor Matthew Morrison; Smashing Pumpkins perform.

Actor Ricky Gervais; actress Jordana Brewster; Elle King performs; Boz Scaggs sits in with The Roots.

Actor Michael Douglas; actress Kat Dennings; St. Vincent performs.

Actor Louis C.K.; actress Sophia Bush; Who Is Fancy performs.

Actress Julia Louis-Dreyfus; actor Scott Eastwood; Flo Rida performs with The Roots.

Actor Nikolaj Coster-Waldau; Madonna performs.

Actor Kevin James; actress Vanessa Hudgens; illusionist Dan White.

Actor/musician LL Cool J; actress Rose Byrne; rapper Big Sean.

Actress Blake Lively; producer Brian Grazer; comic Nate Bargatze; Weird Al Yankovic performs with The Roots.

Actor Russell Crowe; NJ governor Chris Christie; musician Kenny Chesney performs.

Actor Chris Evans; comedy troupe Monty Python; LunchMoney Lewis performs with The Roots.

Actor Chris Pratt; actress Elizabeth Olsen; "Fallonventions."

Actor Robert Downey Jr.; author Fran Lebowitz; Zac Brown Band performs.

Actor Jeremy Renner; actress; Edie Falco; Tori Kelly performs

Actress Kristen Wiig; actor Thomas Middleditch; Josh Groban performs

Actress Scarlett Johansson; comic David Steinberg; Blur performs.

Actress Helen Hunt; actor Jesse Eisenberg; My Morning Jacket performs.

Actor Jack Black; TV personality Melissa Rivers; comic Jeff Garlin.

Actress Sofia Vergara; actor James Marsden; Fetty Wap performs.

Actress Kerry Washington; actor Jesse Tyler Ferguson; Noel Gallagher performs.

Actress Jane Fonda; rapper Sean "Diddy" Combs; The Vaccines perform; Jeff Bradshaw performs with The Roots.

U2 performs

Actress Charlize Theron; journalist Tom Brokaw; Death Cab for Cutie performs.

Actress Anna Kendrick; actor Terry Crews; Nate Ruess performs with The Roots; Unlocking the Truth performs with The Roots.

Actress Rebel Wilson; actress Rosie Huntington-Whiteley; Faith No More performs.

TV show host Bill O'Reilly; Snoop Dogg performs with The Roots.

Actress Queen Latifah; actor Sam Rockwell; a performance from "Something Rotten!"

Actor Hugh Jackman; actor Nick Offerman; Janelle Monáe performs with The Roots.

Actor Jamie Foxx; actress Carla Gugino; Jamie Foxx performs with Kid Ink.

Actor David Duchovny; comic Jeff Foxworthy; Pitbull performs; Kevin Eubanks performs with The Roots.

Actor Dwayne Johnson; Meghan Trainor performs with John Legend.

Musician Sting; actor Kevin Connolly; scientist Kevin Delaney.

Actress Melissa McCarthy; Ed Sheeran performs; Terence Blanchard performs with The Roots.

Actor Jude Law; actress Bryce Dallas Howard; Florence and the Machine performs.

Actor Jason Statham; actor Adrian Grenier; comic Elayne Boosler.

Actor John Cusack; actress Chita Rivera; Ricky Martin performs.

Actress Amanda Seyfried; actor Marlon Wayans; Jason Derulo performs with The Roots.

Actors Larry David and Jason Alexander; actress Natasha Leggero; Alabama Shakes perform.

Actor Denis Leary; actress Molly Shannon; Kacey Musgraves performs.

TV host Whoopi Goldberg; actor Christian Slater; Of Monsters and Men perform.

Actor David Spade; actress Jennette McCurdy; A$AP Rocky performs with The Roots.

Actress Lena Dunham; comic Colin Quinn.

Actor Aziz Ansari; actress Taylor Schilling; Adam Lambert performs; Larry Campbell performs with The Roots.

Actor Billy Crystal; Courtney Barnett performs.

Actor Mark Ruffalo; actor Alan Rickman; James Taylor performs.

Actor Colin Farrell; actor Jason Schwartzman; Elmo.

Actor Vince Vaughn; comic Jim Gaffigan; Ryn Weaver performs.

Actor Seth MacFarlane; actress Amber Heard; Leon Bridges performs.

Actor Channing Tatum; actor Mo Rocca; X Ambassadors performs.

Actor Alan Cumming; actress Carey Mulligan; Ludacris performs with The Roots.

Actor Will Forte; musician Adam Horovitz; TV personality Jeremy Wade.

Actress Helen Mirren; actor Oscar Isaac; Wale performs with The Roots.

Actor Ethan Hawke; TV personalities Willie and Korie Robertson; Alt-J performs.

Musician Pharrell; TV producers Roma Downey and Mark Burnett; Milky Chance performs.

First lady Michelle Obama; actor Matthew Morrison; Smashing Pumpkins perform.

Actor Ricky Gervais; actress Jordana Brewster; Elle King performs; Boz Scaggs sits in with The Roots.

Actor Michael Douglas; actress Kat Dennings; St. Vincent performs.

Actor Louis C.K.; actress Sophia Bush; Who Is Fancy performs.

Actress Julia Louis-Dreyfus; actor Scott Eastwood; Flo Rida performs with The Roots.

Actor Nikolaj Coster-Waldau; Madonna performs.

Actor Kevin James; actress Vanessa Hudgens; illusionist Dan White.

Actor LL Cool J; actress Rose Byrne; Big Sean performs.

Actress Blake Lively; producer Brian Grazer; comic Nate Bargatze; Weird Al Yankovic performs with The Roots.

Actor Russell Crowe; New Jersey Gov. Chris Christie (R); Kenny Chesney performs.

Actor Chris Evans; comedy troupe Monty Python; LunchMoney Lewis performs with The Roots.

Actor Chris Pratt; actress Elizabeth Olsen; "Fallonventions."

Actor Robert Downey Jr.; author Fran Lebowitz; Zac Brown Band performs.

Actor Jeremy Renner; actress Edie Falco; Tori Kelly performs.

Actress Kristen Wiig; actor Thomas Middleditch; Josh Groban performs.

Actress Scarlett Johansson; comic David Steinberg; Blur performs.

Actress Helen Hunt; actor Jesse Eisenberg; My Morning Jacket performs.

Actor Jack Black; TV personality Melissa Rivers; comic Jeff Garlin.

Actress Sofia Vergara; actor James Marsden; Fetty Wap performs.

Actress Kerry Washington; actor Jesse Tyler Ferguson; Noel Gallagher performs.

Actress Jane Fonda; rapper Sean "Diddy" Combs; The Vaccines perform; Jeff Bradshaw performs with The Roots.

U2 performs.

Actress Charlize Theron; journalist Tom Brokaw; Death Cab for Cutie performs.

Actress Anna Kendrick; actor Terry Crews; Nate Ruess performs with The Roots; Unlocking the Truth performs with The Roots.

Actress Rebel Wilson; actress Rosie Huntington-Whiteley; Faith No More performs.

TV show host Bill O'Reilly; Snoop Dogg performs with The Roots.

Actress Queen Latifah; actor Sam Rockwell; a performance from "Something Rotten!"

Actor Hugh Jackman; actor Nick Offerman; Janelle Monáe performs with The Roots.

Actor Jamie Foxx; actress Carla Gugino; Jamie Foxx performs with Kid Ink.

Actor Dwayne Johnson; Meghan Trainor performs with John Legend.

Musician Sting; actor Kevin Connolly; scientist Kevin Delaney.

Actress Melissa McCarthy; Ed Sheeran performs; Terence Blanchard performs with The Roots.

Actor Jude Law; actress Bryce Dallas Howard; Florence and the Machine performs.

Actor Jason Statham; actor Adrian Grenier; comic Elayne Boosler.

Hillary Clinton, Dakota Johnson, Fetty Wap

Actress Amanda Seyfried; actor Marlon Wayans; Jason Derulo performs with The Roots.

Actors Larry David and Jason Alexander; actress Natasha Leggero; Alabama Shakes perform.

Actor Denis Leary; actress Molly Shannon; Kacey Musgraves performs.

TV host Whoopi Goldberg; actor Christian Slater; Of Monsters and Men perform.

Actor David Spade; actress Jennette McCurdy; A$AP Rocky performs with The Roots.

Actress Lena Dunham; comic Colin Quinn.

Actor Aziz Ansari; actress Taylor Schilling; Adam Lambert performs; Larry Campbell performs with The Roots.

Actor Billy Crystal; Courtney Barnett performs.

Actor Mark Ruffalo; actor Alan Rickman; James Taylor performs.

Actor Colin Farrell; actor Jason Schwartzman; Elmo.

Actor Vince Vaughn; comic Jim Gaffigan; Ryn Weaver performs.

Actor Seth MacFarlane; actress Amber Heard; Leon Bridges performs.

Actor Channing Tatum; actor David Oyelowo; X Ambassadors performs.

Arnold Schwarzenegger, Mike Birbiglia, Major Lazer

Mark Wahlberg, Chris Colfer, Morrissey

Paul Rudd, Echosmith

LeBron James, Tiny Fey & Amy Poehler, OMI

Amy Schumer, Ian McKellen, Alan Jackson

Bill Hader, Years & Years

Ryan Seacrest, Trevor Noah, Tig Notaro

Adam Sandler, Judd Apatow, Giorgio Mordoder

Jake Gyllenhaal, Josh Gad, James Bay

Norm Macdonald, JoAnna Garcia Swisher, Jeremih & Flo Rida

Kate Holmes, David Wain & Michael Showalter, Sage the Gemini featuring Nick Jonas

Rachel McAdams, Michael Pena, Robert Klein

Tom Cruise, Dick Cavett, Ashley Monroe, Buddy Guy

Danny DeVito, Simon Pegg, George Ezar, Donn

Jason Segel, Amy Sedaris, Alessia Cara

Ice-T, Bella Thorne, Ms. Lauryn Hill

Kevin Bacon, Mel B, Russell Howard

Meryl Streep, Jerrod Carmichael, Albert Hammond Jr.

Don Rickles, Kate Mara, Penn & Teller

Ice Cube, Mamie Gummer, Nathaniel Rateliff & the Night Sweats

Salma Hayek, Tim Gunn, Christopher Cross

Steve Buscemi, Taylor Kitsch, Jon Rineman

Chris Meloni, Luke Bryan, Boney James

Kristen Stewart, Jim Belushi, Yolanda Adams

Ben Kingsley, Henry Cavill, Reba McEntire

Paul Giamatti, Alicia Vikander, Robin Thicke

Kevin Spacey, Keegan-Michael Key, Monroe Martin

Zac Efron, Fran Lebowitz, Amazing Grace

Taraji P. Henson, Edward Burns, Sam Hunt

Heidi Klum, David Oyelowo, Carly Rae Jepsen

Rachel Maddow, Artie Lange, Michael McDonald & the Doobie Brothers

Jason Schwartzman, Tatiana Maslaney, Dan White

Gov. Chris Christie, Victoria Justice, Gark Clark Jr.

Liev Schreiber, Elle Fanning, Vince Staples

Justin Bieber, Salman Rushdie

Jason Sudeikis, Bel Powley, Brad Paisley, Joe Bonamassa

Steve Harvey, Alison Brie, Florida Georgia Line

Richard Gere, Jessica Simpson, Keith Urban

Justin Timberlake, Ellen DeGeneres, Macklemore & Ryan Lewis

Andy Samberg, Carrie Underwood

Donald Trump, Terrence Howard, Pharell Williams

Benicio Del Toro, Jessica Alba, Miguel

Robert De Niro, Ariana Grande, Duran Duran

Hillary Clinton, Dakota Johnson

Kaley Cuoco, Wesley Snipes, Chris Cornell

Keith Richards, Emma Roberts, Kevin Delaney

Anne Hathaway, Anthony Anderson, A Great Big World

James Spader, Andrew Rannells, Brian Regan

Joseph Gordon-Levitt, Chris Hardwick, Big Grams, Mickey Dolenz

Olivia Wilde, Fred Savage, Walk the Moon

Rob Lowe, Kat Dennings, Beth Behrs, Hozier

Julianne Moore, Mark-Paul Gosselaar, DNCE

Julianna Marguiles, Andy Cohen, John Scofield

Miley Cyrus, Sam Rockwell, Disclosure

Seth Rogen, Victor Cruz, CHVRCHES

Hugh Jackman, Shaquille O'Neal, Talib Kweli, Warren Haynes

Lady Gaga, Ronda Rousey, Hailee Steinfeld