Solange Knowles didn't go crazy on Jay Z this year, but she did go all out with her Met Gala ensemble!

Beyonce's little sis wore printed circle dress, and she posted a few photos on Instagram and wrote, "When @cartier is your date, and Giles is your dress," but her hubby Alan Ferguson was actually her plus one. Lady Gaga followed suit with a similarly poufy custom Balenciaga by Alexander Wang frock, and she walked the carpet with the designer himself. Gaga also hosted the Met Ball after party later in the evening ... fun!

Sarah Jessica Parker caught everyone's attention with a massive headdress, and Katy Perry turned heads for a different reason ... her outfit completely sucked! And we're still not digging the Kris Jenner-inspired do:


And later in the evening Katy and Gaga posed for a selfie with the Queen of Pop herself ... who knew this trio could set aside their differences (and egos?!) and make nice? Madge posted the pic first and wrote, "Girls night out.......... Kissing the Ring........Finally! #metball," and Katy uploaded the same shot later and wrote, "Dropping our single tomorrow ... #stolethispicfromM #MONSTERCATREBELHEARTS."