Reese celebrated her upcoming 40th birthday with a party in Hollywood on Saturday night, and was joined by endless celebrity friends, including Taylor Swift, Kate Hudson, Isla Fisher, Courteney Cox, Laura Dern, Cheryl Strayed, Chelsea Handler, Nicole Kidman, Olivia Munn, Sarah Paulson, Mindy Kaling, Elizabeth Banks, Chris Martin, Jason Bateman, Conan O’Brien…. A few of the guests, including Kate Hudson, have posted some snaps from the night on their Instagrams – see them below – and Vanity Fair writer Derek Blasberg has shared a video snippet of Reese singing along to ‘Sweet Home Alabama’! While we don’t usually post about Reese’s personal life here at GRW, this is harmless and fun enough to be ok 😉

Reese Witherspoon Gets a Head Start on Her 40th Birthday with a Star-Studded Bash – and a Private Taylor Swift Concert

Reese Witherspoon’s 40th birthday party on Saturday was a rockin’ bash indeed – filled with stars, sexy jazzy music and a Taylor Swift performance, just for her.

The party, at the Warwick, in Hollywood, California, kicked off at 7:30 p.m., as Witherspoon (who turns 40 on Tuesday) arrived with husband Jim Toth, a source tells PEOPLE.

“Reese was smiling and seemed excited about her party. She wore a sparkly cocktail dress and looked amazing,” the source says.

Witherspoon also shared a Snapchat video with her mom as they drove to the party.

As guests filled in afterward, the superstar guest list grew longer and longer. Jennifer Aniston and husband Justin Theroux, Courteney Cox, Matthew McConaughey and wife Camila Alves, Robert Downey Jr. and wife Susan Downey, Nicole Kidman and husband Keith Urban, Tobey Maguire and wife Jennifer Meyer, Jason Bateman and Swift and Kate Hudson all dropped by.

“A live band played sexy jazz music as guests arrived,” the source tells PEOPLE.

Hudson captured the ecstatic spirit of the evening with an Instagram collage from the party, posted very early Sunday, with the hashtags “#TequillaFirst #PostingLater #SaturdayNight #ImSoExcitedToGetIntoBedIDontEvenKnowWhatToDoWithMyself #NotWashingMyFace #GoodNight.”

And while some guests brought presents, the source says, perhaps the best gift was when, “later in the evening, Taylor performed for Reese.”

Hudson shared several videos of Swift performing on Snapchat.

“This beauty gave a little surprise for our bday,” Hudson wrote on one video, adding “Happy birthday Reese, we love you!”

Witherspoon also supplied some musical entertainment on her big night, singing “Sweet Home Alabama” with Urban.

Hudson left the party with pal Erin Foster, who jokingly gave her a mini interview on the ride home.

“What’s the percentage of guys who you’ve hooked up versus guys people think you’ve hooked up with?” Foster asked.

“Five percent,” Hudson answered.

“Don’t you think being a movie star you should be going home with a hot guy instead of me?”

Hudson smiled, “Yes.”

The actress later shared a video of herself playing with Snapchat’s filters, writing that she was getting home after 2 a.m., noting it was “past our bedtime.”

“It was a great party. When Reese left at 2 a.m., she was in the best mood,” the source adds. “You could tell that she had the best time celebrating her birthday.”

– People

Reese Witherspoon sings ‘Sweet Home Alabama’ for 40th

Birthday gal Reese Witherspoon treated her guests to something special Saturday night at a Hollywood club.

The Sweet Home Alabama movie actress, who turns 40 on Tuesday, brought her mom along for the fun. Among the other attendees: Kate Hudson, Taylor Swift and Laura Dern.

Keith Urban was on guitar during the proceedings on stage and at some point, party girl Swift also took to the microphone. Swift had spent the previous night dancing and singing with friends on the floor of the Las Vegas club where her boyfriend, Calvin Harris, had a show.

Vanity Fair writer Derek Bl;asberg posted a video of Reese’s performance of the Lynyrd Skynyrd song of the same title as the movie on Instagram. He wrote, “You can take the girl out the South, but you can’t take Sweet Home Alabama out the girl! HAPPY BIRTHDAY.” Check out Urban behind the, ahem, singer.

– USA Today