The two singers got all dressed up to celebrate the holiday – Leona was a fortune teller and Rachel was an angel.
Rachel was joined at the event by her husband Kevin Lazan.
Other music stars in attendance included Frankie, Fancy Hagood, Fletcher, Symon, Nash Overstreet with his brother Chord (pictured below), Ryan Beatty, Gabe Sporta, Bonnie McKee, Zane Carney, and The Struts‘ Jed Elliott, Gethin Davies, and Adam Slack.
Guests at the event, including Frankie and her band, snacked on Pasta Chips throughout the night.
FYI: Rachel carried a Milly clutch with her costume.