Taylor Swift‘s birthday celebrations continue!The musician, who turned 30 on Friday, was treated to a surprised birthday party from friends and songwriting collaboratorsJack Antonoffand Laura Sisk when she joined them for a studio session on Wednesday.“Walked into the studio to a surprise birthday party from these two @jackantonoff & @sharp_stick – it’s equally wild and cozy to think it was the three of us in a room making a song called Lover here last year. ♥️,” Swift wrote in the caption for a pair of photos from the surprise.In one photo, Swift sits on a couch in between Antonoff, 35, and Sisk, who each hold a big pink balloon. Swift holds a cake with the words “Happy Birthday” written in icing on top — at least her third birthday cake, as Elvis Duransurprised her with a giant cake at Jingle Ball, and she hadanotherat her holiday-themed birthday party with thefaces of her three cats.The “Lover” singer tagged her brotherAustin Swiftin the second photo, which showed massive balloons that read “Happy Birthday” crowding the studio space.Swift celebrated turning “THIRTAY” on the day of her birthday after she performed at Z100’s Jingle Ball at Madison Square Garden with a bash at the Oscar Wilde restaurant in New York City.A source told PEOPLE the following day that Swift was excited about hitting the milestone year.“Taylor has been very excited about turning 30. She sees it as something positive. She had a dinner bash with friends last night and she had the best time,” the source said.The “You Need to Calm Down” singer was joined with several of her famous friends for the fete, including fellow Jingle Ball performersHalsey, 5 Seconds of Summer andCamila Cabello, as well asRyan ReynoldsandBlake Lively,Queer EyestarsAntoni PorowskiandJonathan Van Nessand supermodelGigi Hadid.Taylor Swift/Instagram“Honestly spending my 30th with the fans who have made my life what it is at jingle ball, then throwing the most aggressive holiday party known to womankind… I just.. seriously feel so lucky for you all and will spend forever trying to find ways to say thank you. cries in Christmas tree,” Swiftwrote on Instagramalongside several photos from the bash.The Grammy winner has had a busy start to her 30th year.She announced just two days after her birthday that she will be headlining the iconic Glastonbury Festival for the event’s 50th anniversary.“I’m ecstatic to tell you that I’ll be headlining Glastonbury on its 50th anniversary – See you there! ?,” she wrote in theInstagram announcement.Then on Monday, swiftwalked the red carpetat the premiere forCatsin New York — and she was alsospotted walking hand-in-hand with boyfriendJoe Alwynafterwards. The pair begansecretly datingin the fall of 2016.

Taylor Swift‘s birthday celebrations continue!

The musician, who turned 30 on Friday, was treated to a surprised birthday party from friends and songwriting collaboratorsJack Antonoffand Laura Sisk when she joined them for a studio session on Wednesday.

“Walked into the studio to a surprise birthday party from these two @jackantonoff & @sharp_stick – it’s equally wild and cozy to think it was the three of us in a room making a song called Lover here last year. ♥️,” Swift wrote in the caption for a pair of photos from the surprise.

In one photo, Swift sits on a couch in between Antonoff, 35, and Sisk, who each hold a big pink balloon. Swift holds a cake with the words “Happy Birthday” written in icing on top — at least her third birthday cake, as Elvis Duransurprised her with a giant cake at Jingle Ball, and she hadanotherat her holiday-themed birthday party with thefaces of her three cats.

The “Lover” singer tagged her brotherAustin Swiftin the second photo, which showed massive balloons that read “Happy Birthday” crowding the studio space.

Swift celebrated turning “THIRTAY” on the day of her birthday after she performed at Z100’s Jingle Ball at Madison Square Garden with a bash at the Oscar Wilde restaurant in New York City.

A source told PEOPLE the following day that Swift was excited about hitting the milestone year.

“Taylor has been very excited about turning 30. She sees it as something positive. She had a dinner bash with friends last night and she had the best time,” the source said.

The “You Need to Calm Down” singer was joined with several of her famous friends for the fete, including fellow Jingle Ball performersHalsey, 5 Seconds of Summer andCamila Cabello, as well asRyan ReynoldsandBlake Lively,Queer EyestarsAntoni PorowskiandJonathan Van Nessand supermodelGigi Hadid.

Taylor Swift/Instagram

Taylor Swift

“Honestly spending my 30th with the fans who have made my life what it is at jingle ball, then throwing the most aggressive holiday party known to womankind… I just.. seriously feel so lucky for you all and will spend forever trying to find ways to say thank you. cries in Christmas tree,” Swiftwrote on Instagramalongside several photos from the bash.

The Grammy winner has had a busy start to her 30th year.

She announced just two days after her birthday that she will be headlining the iconic Glastonbury Festival for the event’s 50th anniversary.

“I’m ecstatic to tell you that I’ll be headlining Glastonbury on its 50th anniversary – See you there! ?,” she wrote in theInstagram announcement.

Then on Monday, swiftwalked the red carpetat the premiere forCatsin New York — and she was alsospotted walking hand-in-hand with boyfriendJoe Alwynafterwards. The pair begansecretly datingin the fall of 2016.

source: people.com