CHAMPAIGN, Ill. — What fun it is to laugh and sing — and laugh and sing, and laugh and sing — if you’re a University of Illinois student caroler this holiday season.

The students were taking thousands of holiday song requests by phone 24 hours a day during finals week, singing “Jingle Bells,” “All I Want for Christmas” and “Frosty the Snowman” from a makeshift phone bank in their festive dorm lounge.

The “Dial-a-Carol” phone lines opened at 12:01 a.m. Dec. 13, with the first call coming in a minute later, and stayed open until 11:59 p.m. Dec. 19.

It’s rare for more than five minutes to pass between calls, with students getting most giddy when it’s time to sing “Feliz Navidad,” swaying their hips and snapping their fingers as they gather around the phone.

About 70 volunteers who live in Snyder Hall take hourslong shifts, some in the middle of the night, to continue a 52-year-old tradition that brought in 4,000 calls last year.

At times, students are singing into three phones simultaneously, a chorus of carols filling the dorm lobby.

Nearly 500 calls came in on the first day alone. A woman in Japan asked for “Santa Claus Is Coming to Town,” while Mark from Illinois asked for “Jingle Bells.”

“We’re pros at that song,” said junior Heather Sears, prompting six carolers to run to the phone to sing it.

As soon as they finished, the phone rang again, this time a request for “Rudolph the Red-Nosed Reindeer” from a middle school music class in Marietta, Ga.

“Are you guys ready?” Sears said to fellow carolers. “3. 2. 1.” And they belted out the song, some of them peeling away before it was over to answer another call.

The music teacher said she heard about Dial-a-Carol through Facebook.

“It’s been on my calendar for several weeks. The students picked three carols and we voted and Rudolph won,” said teacher Jennifer Stepp. “They did great.”

Anyone, from anywhere, can request a carol or holiday song, and, in most cases, it’s in the students’ binder of 41 songs. If they don’t know the song, they look it up on YouTube and play a recording.

Callers also can request that the volunteers call someone else to deliver a song.

During one afternoon shift, callers included a radio host in Ireland, toddlers at a day care center, and U. of I. classmates calling from a cafeteria during lunch. The carolers were giggly, fueled by coffee and Mountain Dew as they avoided studying for finals.

Keith Cunningham, a radio host in Dublin, stumped the students with a request for “Fairytale of New York,” a popular Christmas ballad in Ireland.

“You have definitely given us a challenge,” Daniel Quock, Snyder Hall’s resident director, told the caller.

He found the song and lyrics online, however, and sang along as it played. The radio host sang, too.

“For a first attempt at ‘Fairytale of New York,’ a difficult song to sing, they absolutely nailed it,” Cunningham said. “I am very impressed. Very impressed.”

Legend has it that the “Dial-a-Carol” tradition was started by a Snyder Hall secretary, Betty Gordon, who thought it would be fun to play carols over the phone to friends.

The operation hasn’t changed much since then. While students used to only be able to deliver calls locally, now they can call anywhere through a free online calling service.

When he was governor, James Thompson was among the callers one year. He said that he thinks he requested they sing “Silent Night.”

The most popular song last year was “Jingle Bells,” with about 550 requests, and it was at the top again this year.

“Have we had any (Justin) Bieber requests so far?” freshman Warren D’Souza asked the other carolers.

“No, thank God,” two replied in unison.

In another update, the students kept a “Mariah-o-Meter” on the wall, tracking the number of requests for Mariah Carey’s version of “All I Want for Christmas is You.” There were 15 requests in the first 12 hours.

The phone line gets its share of prank calls. Michael Jackson’s “Thriller” and Britney Spears’ “Oops, I Did it Again” can’t be considered carols by anyone’s standards.

“Someone called last year and asked for the ‘12 Days of Christmas,’ ” said senior Adam Blackburn, the organizer of this year’s effort. “That is a long song. We started singing and they hung up at some point.”

The students have since decided they will only sing the lyrics for the 12th day.

The carolers keep a handwritten list of “funny responses” on the wall: “Are you a real person?” “Do you have to be drunk or high to do this?”

Snyder Hall, actually, is a substance-free dorm. But certainly some of the callers — particularly those who call in the middle of the night — may have had a few drinks.

“I had a caller from Vegas and he was like, ‘I want a Bing Crosby song, ‘It’s a Wonderful Life,” and it has the line “Baby, it’s cold outside,” recalled sophomore Clare Curtin. “I was thinking to myself, ‘That is three different songs. You are totally drunk.’”

Utah resident Adam Wills, who has never been to the U. of I. campus, has been calling “Dial-a-Carol” for six years after a friend told him about it. His 8-year-old son has asked that they request “Jingle Bells, Batman Smells” this year.

Wills, 41, said he looks forward to calling even though he can turn on the radio or walk into any shopping mall and hear carols.

“The idea of a bunch of college students in the middle of finals taking their time to sing to us, that is what Christmas is all about,” Wills said. “It is about the simple things. Calling someone on the phone and asking them to sing, and they do it: That is really cool.”

Senior Kasia Stelmach, 22, sang for at least five hours one day, her fourth year participating in the program.

“It’s a nice study break,” she said. “You can make a fool out of yourself and be totally OK with it.”

As if on cue, caroler Curtin began singing “The Chipmunk Song (Christmas Don’t be Late)” — in full chipmunk voice — into the phone.

A few students joined in the singing. And the rest just laughed.