It’s that time of year when the world falls in love, every song you year seems to say, Merry Christmas.

These are the words of holiday favorite “The Christmas Waltz.”

Indeed, there is a special time of year when every song seems to have a holiday theme. In honor of the traditions of the season, the music department will present its annual Holiday Festival of Music Saturday afternoon at Stephens Auditorium, featuring an irresistible lineup of holiday music.

In their 43rd year of presenting the holiday concert, the department plans to present a show that features 250 musicians from a variety of media.

Among the vocal groups performing will be the Iowa State Singers, Men’s Glee Club, University Chorus, Oratorio Choir and the jazz group Off the Record.

“Most of these choirs have really been in it every year,” said Robert Molison, professor of music.

Although all the choirs will also perform individual numbers, three of the choral songs (“Behold a Star” by Felix Mendelssohn; “Fanfare for a Holiday Festival by former Iowa State choral director, Robert McCown; and an arrangement of “We Wish You a Merry Christmas” by the Canadian Brass) will be performed by all of the choirs under the direction of Molison.

“[The pieces] are sparkly, light-hearted arrangements of well-known things,” Molison said.

In addition to the well-known tunes, there will also be some songs presented that aren’t traditional American favorites.

During the second half of the concert, all five choirs will take turns performing holiday songs from places all over the world.

Molison said the Men’s Glee Club will perform a Spanish piece called “Ya viene Ya Vieja,” and the University Chorus will sing a song called “Gower Wassail,” which he refers to as “a drinking song.”

Vocal choirs aren’t the only ones that will be adding to the holiday atmosphere at the festival.

Molison said instrumental choirs such as the Flute choir, directed by flute professor Elizabeth Sadelik, and the Bassoon ensemble, directed by oboe and bassoon professor Kevin Schilling, will be positioned in balconies around the auditorium. They will accompany the choirs and provide a “surround sound” experience for the audience.

“We’re trying to use the entire hall as a performing space,” Molison said.

And it won’t just be a performing space for all the choirs and instrumentalists.

In the middle of the concert and at the end, audience members will be invited to sing traditional Christmas carols with the rest of the performers. Molison said the sing-a-longs will be accompanied by organ professor Lynn Zeigler.

Even though it’s the last event on the program, the audience sing-a-long won’t be the last musical presentation of the afternoon.

After the last Christmas carol has been sung, the Iowa State Trombone Choir will take the stage to play multi-part trombone arrangements of familiar Christmas carols as audience members retreat toward the doors.

“[The Trombone choir] just plays for the holiday concert and at the music building after the last general recital of the year,” trombonist John Gruber said.

Because the choir only plays during the holiday season, members consistently wear Santa hats during all of their performances. Unlike uniforms that are required for some other ensembles, the uniforms for the Trombone ensemble haven’t been much of a financial burden.

“I already had my own [Santa hat],” Gruber said. “Most people have one or borrow one. They’re just the kind you get at Wal-Mart.”

The Holiday Festival of music will be held at Stephens Auditorium Saturday at 3 p.m. Tickets are $5 for students, children and seniors and $8 for non-students.