Not many people know what's going on behind the scenes with Utah's "American Idol" star, David Archuleta, because the show sequesters its contestants and their families from the media.

But the one man who has been in constant communication with Archuleta is his Salt Lake-based voice coach, Dean Kaelin.

Archuleta, who along with the seven remaining finalists will sing tonight, has relied on Kaelin, calling him several times a day for voice warm-ups or consultation about song selection and performance. Sometimes he calls him just moments before going on stage.

The Kaelin-Archuleta team has made a remarkable run through the contest, but it has not been without its challenges. Archuleta caught a strep throat infection a couple of weeks ago that persisted through two performances on "American Idol."

"Imagine what that would be like, stepping on stage sick," Kaelin says. "It was petrifying. A lot of people didn't know he was sick. He was congested. We just tried to keep his throat loose. We warmed up several times a day."

Archuleta was still recovering from the infection when he suffered another setback — he momentarily forgot the lyrics to the Beatles' "We Can Work It Out." Just minutes before going on stage, he sang the song over the phone to Kaelin. He hesitated in a couple of places, but said nothing about his difficulty with the words. After hanging up the phone, Archuleta searched frantically for a copy of the lyrics, but couldn't find one before he had to go on national TV.

"They ('Idol') keep them going all day," Kaelin says. "The reason David forgot the words is because they had him going to photo shoots and shooting commercials. He had so many other things to think about."

Archuleta, the youngest finalist at 17, has an even busier schedule than other contestants because he is required, under child labor laws, to attend three hours of school each day. "That puts him at a disadvantage," Kaelin says.

There are days when Archuleta is awakened at 6 a.m., in the studio by 7 and doesn't return to his room until 10:30 p.m., according to Kaelin. Contestants are given a list from which to choose their next song performance, and from Thursday to Saturday they practice it. Meanwhile, they are in and out of the recording studio and shuttled to various appearances.

After his disappointing "We Can Work It Out" showing, Archuleta "felt he let his fans down," Kaelin says. "That was his biggest concern. But people rallied around him."

Archuleta rebounded with a flawless performance of "The Long and Winding Road" that left judges gushing again.

"I've always known David was talented," says Kaelin, whose students include two other "American Idol" finalists (Carmen Rasmusen and John Praetor). "I just told him to go down there and have some fun and see if it can roll into anything else, because he's always wanted to do something with his music. Then he started getting attention, and people are picking him in the top two or three. It caught us all by surprise. He has really been surprised."