Katy Perry, Pharrell Williams, Dave Grohl, and other music stars join Ringo Starr and Paul McCartney on stage for A Grammy Salute To The Beatles event; Zac Efron, Taylor Swift, Michael B. Jordan, Miles Teller, and more attend the premiere and after party for That Awkward Moment; Jessica Alba, Neil Patrick Harris, Gwyneth Paltrow, and others from Hollywood's A-list attend the Hollywood Stands Up To Cancer fundraiser hosted by Reese Witherspoon—catch up on Monday and Tuesday's top L.A. events with this edition of Last Night's Parties.

Katy Perry Heidi Klum Emma Roberts Gwyneth Paltrow Diane Kruger Reese Witherspoon Anne Hathaway john mayer Robin Thicke lucky strike Selena Gomez Alicia Keys Kate Beckinsale Jessica Alba Cash Warren Drew Barrymore Sean Penn Tom Hanks Zac Efron Taylor Swift Zooey Deschanel Ashley Tisdale Christina Aguilera John Legend Cameron Silver Joshua Jackson Jamie Foxx chris lowell Rita Wilson Justin Bartha Jessica Szohr Yoko Ono LL Cool J Neil Patrick Harris Les Moonves Paul McCartney Stevie Wonder Debby Ryan Sean Lennon Lily Collins spike jonze Eric Idle Anna Kendrick Mickey Madden Johnny Depp Pharrell Williams Alyssa Milano Peter Frampton Keith Urban Ringo Starr Jeff Bridges Los Angeles Convention Center Ryan Eggold Nancy Shevell Adam Levine Dave Grohl Jesse Tyler Ferguson Imogen Poots Tia Mowry Tal Ronnen Behati Prinsloo Dave Stewart Barbara Bach Joe Walsh David O. Russell Alana Stewart Jim Toth Amanda Michalka Miles Teller Sasha Alexander Ken Jeong Chrissy Teigen David Burtka Jeff Lynne Neil Portnow Michael B. Jordan Brad Paisley Clark Gregg Ed Sheeran James Valentine Mohammed Al Turki Gary Clark Jr Justin Mikita Emily Procter Julie Delpy Elijah Kelley Terence Winter Alan Ritchson Randy Sklar Marlien Rentmeester Annie Lennox Andy Griffith Tracy Letts Writers Guild Theater Stephanie Johnson Nicholas Jarecki Justin Nappi Dhani Harrison Regal Cinemas at L.A. LIVE