Murrieta Valley High School band director Rick Lorenzen was remembered as a strict, but compassionate taskmaster by members of the band, who gathered Monday evening at the school, about 24 hours after he died.

Lorenzen, 52, was found dead on campus Sunday. Students arriving for an evening practice found him unresponsive at his desk, according to the Murrieta Valley Unified School District spokeswoman.

While a cause of death has yet to be determined, Murrieta Valley High Principal Renate Jefferson said preliminary indications point to a heart attack. Jefferson said Lorenzen's brother told her their father died of a heart attack in his early 50s.

"How incredibly tragic to find ourselves today so unexpectedly without our band teacher," Jefferson told a group of about 200 band members and parents gathered Monday. " ... We lost a friend, we lost a colleague and we lost a great band director whose passion has been instilled in you."

Members of the band's leadership team said Monday was a tough day.

"Sitting in his office and looking at his chair (was difficult)," said drum major David Neverman, a 17-year-old senior. "Realizing he's really gone. I think most everyone is still in shock."

But, as cliched as it sounds, the band must play on: There is a halftime show to perform at Friday night's football game and a competition Saturday.

"We're going to turn this into a motivational tool," David said.

Band president Neda Bionghi said Lorenzen was like a father to band members, who spend numerous hours together during the school year.

Denise Hains, president of the booster club for the 125-member Crimson Cadets, said that when Lorenzen was unhappy with the effort he was seeing, he would use his "daddy voice."

"He had a gift for inspiring, and they responded to it," said Hains, who has two sons in the band. "He loved them."

The district's crisis counseling team and MVHS counselors were on campus Monday to talk with students and staff.

Lorenzen, a music educator for 27 years, came to Murrieta Valley in 2007. He was previously band director for five years at Diamond Bar High School, six years at Bonita Vista High in Chula Vista, six years at Orange Glen High in Escondido and seven years at Carlsbad High.

Jaime Bowden, a 1995 graduate of Orange Glen High School who now lives in Martinsburg, W.Va., said she learned a lot from Lorenzen during the four years she spent in Orange Glen's band. After graduation, she said, she returned for two years to help coach students under his direction.

"I had a lot of respect for him, both as a teacher and as a musician," Bowden said, adding that Lorenzen taught her "how to be a better musician ---- to not just play the music, but to actually feel it."

Jefferson said there was an outpouring of calls and e-mails of support from bands and directors from throughout the state.

"They all talked about how much he talked about our program, our school and, most importantly, our students," Jefferson said. "That's what he was passionate about, teaching. He was passionate about passing that love of music on to you."

Lorenzen conducted the concert band, marching band, symphony orchestra and color guard at MVHS.

Jefferson said substitutes will fill in for the rest of the year to teach music classes and oversee the band program. A new band director will be hired for next school year.

The halftime show at Murrieta Valley's home football game against Great Oak on Friday will be dedicated to Lorenzen's memory. A celebration of life is scheduled for 4 p.m. Sunday at Murrieta Valley High, 42200 Nighthawk Way.

Lorenzen is survived by one brother, Norm, of Texas.

A memorial page has been set up on Facebook.

As of Monday night, more than 600 people had registered on the page.

Call staff writer Craig Shultz at 951-676-4315, ext. 2625.