Ethan Fitzpatrick, Vienna Dumlao and Angel Husher may have seen "The Sound of Music," but today, they'll be in the actual castle-studded country where the hills are alive with ... well, you can take it from here.

The three Hawai'i Pacific University students, all part of the HPU International Vocal Ensemble or International Chorale, are in Austria as part of a group of 29 Hawai'i-based singers who will perform in concerts honoring the 250th anniversary of Mozart's birth. Today, they were scheduled to tour two castles featured in "The Sound of Music," Schloss Leopoldskron and Hellbrunn Schloss.

At a rehearsal last week, they peppered choirmate Scott Shaub with questions, since he's been to Austria before. He dutifully explained how important a few courtesy phrases, like "danke schoen," can go a long way.

"I'm pretty stoked," Husher said.

With rehearsals and fundraising now behind them, the HPU students are scheduled to perform today at a concert in Salzburg, the town where Mozart was born.

Before the singers left, they held a birthday party for Mozart, complete with cake and a screening of "Amadeus."

Last week, they could be found chattering away at the downtown campus' Warmer Auditorium before a mini-concert for faculty and friends that helped to serve as rehearsal for the Austrian tour. On Sunday, they boarded a plane en route to Germany, where they would catch a bus to Salzburg.

"I've never been so excited in my life," admitted Abe Gruber, adding he has reason to be — he's taking a few weeks off afterward to tour Prague, Amsterdam, Rome, Florence. ... His good friends sitting around the circle smiled at him, dreamily.

Gruber tried to explain how he scraped enough money together to afford the backpacking portion of the trip — "Let me tell ya the great deal on mac and cheese I got," he said — only to be greeted by a chorus of groans.

The students say they've been busy since classes ended, with summer school, part- and full-time jobs, and fundraising for this trip.

As they good-naturedly explain all this, it grows apparent that the crew, all on some form of scholarship through the ensemble, enjoy each other's animated company. They laugh about how they've been given a mandate not to sing too loudly on the buses while they're traveling the Austrian roads.

It's a real concern: This group is known to bust out in song without provocation.

Kala'i Stern is charged with keeping the 29-member group on key. The interim conductor of choral music at HPU expected his gig to be up before the trip, but he was tapped to extend his stay to help with a prestigious task.

They're the only singers from Hawai'i who will be part of a 385-member choir for today's Salzburg performance, one of two Austrian concerts planned for the trip. After that, the Hawai'i contingent will head to Vienna for more sightseeing and another concert.

They plan to distinguish their presence, in performance and in photos to commemorate the concerts: Even though every choir member dresses in black, they're bringing greenery-strewn kukui- nut lei along.

All this is a highlight for the HPU program, just four years old and already having played at Carnegie Hall in New York in 2004. Since HPU doesn't have a music degree program, trips like these take a level of commitment hard to harness for any group of busy young adults, Stern says, but astonishing when you consider that this diverse group of students ranges from marine biology majors to nurses-in-training.

They were invited to perform in Austria after sending in an application, but then had to come up with $100,000 to cover travel and other costs of the trip. HPU ponied up half of that; the rest came through donations and fundraisers.

"Students were fundraising before I was even here, through concerts, car washes; we did caroling gigs through the Christmas season in Waikiki," explained Stern.

While the Island singers won't be performing any Hawaiian music at their concerts, no one will be surprised if somewhere along the line, they break out in a hapa-haole song, like the showstopping finale of their spring concert, another fundraiser.

"We're all divas," Husher said.