From left: Noah, Bill Ray, Tish, Miley, Brandi and Braison Cyrus
The Cyrus family has a lot to be thankful for this year.
is celebrating her 20th birthday on Friday. Her dad, Billy Ray Cyrus, is starring as slick lawyer Billy Flynn in the Broadway hit musical Chicago
. And it looks like (practically) the whole family is together for the occasions.
Photos show Billy Ray – dressed in a tuxedo – his wife Tish and their kids, Miley, 19, Noah, 12, Brandi, 25, and Braison, 18, all posing together backstage at the Ambassador Theater in New York City on Sunday. (Brother Trace is the only one absent.)
"The whole family had a great time," an observer tells PEOPLE.
They came backstage at intermission to spend time with Billy Ray in his dressing room, and again after the show to meet some of his fellow cast members.
Billy Ray, who began his Broadway run recently, told PEOPLE that his family hadn't come to see him yet partly because he wanted to get comfortable in the role. "I gotta get my legs up [before they see it]," he said. "I think everybody's coming in for Thanksgiving. So we'll see what happens."
Now that they've seen it, it seems his family is giving his performance a thumbs-up. "So glad to be back with my daddy (@billyraycyrus) for the first time in 3 MONTHS!! He was so great on broadway," Noah Tweeted
Miley, too, is having a blast in the Big Apple. "What a dope morning. So many fans outside my hotel this a.m. in NYC. If there's this much chaos NOW imagine when I drop this record! #ohsnap," she Tweeted
As for Billy Ray, whose Chicago
run ends Dec. 23, he says taking the part on Broadway has been great fun – and a great challenge.
"I couldn't come up here and do something predictable," he says of the role. "I was offered Rock of Ages,
and my instincts said, 'That's a bit predictable for me.' "
But when the role of Billy Flynn came up, Ray explained, "He's the total opposite of me" – and that was just what he wanted.