Concert with L.A. Phil will continue despite singer’s death

Musicians at Walt Disney Concert Hall, still in shock Tuesday after the sudden death of a choral singer preparing for the West Coast premiere of Louis Andriessen’s “De Materie,” said they will perform as planned on Friday despite the tragedy.

The L.A. County coroner’s department said tenor Jeff Dinsmore, 42, of a Philadelphia chamber choir called the Crossing, was pronounced dead at 11:55 a.m. Monday. Dinsmore and other members of the Crossing had been warming up in a rehearsal room at Disney Hall.

Los Angeles Fire Department officials said paramedics were summoned to Disney Hall about 11 a.m. Monday. Fire officials declined to elaborate on the causes or circumstances of Dinsmore’s death.

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“It’s unfathomable what’s happened,” said Donald Nally, conductor of the Crossing, seven of whose members will carry on as originally scheduled, performing with the Los Angeles Philharmonic.

In a statement Tuesday, the Crossing said Dinsmore’s partner, Rebecca Siler, who also came to L.A. to perform Friday evening, requested that the group perform as planned.

Dinsmore and Nally co-founded the Crossing in 2005. The group, which specializes in new music, has performed throughout the country and is making its Disney Hall debut.

Dinsmore not only sang with the group but also was its head of marketing. He also was the head of marketing for Opera New Jersey.

It remains unclear if the singer had any health problems. Nally said he was unaware of any medical conditions that could have caused Dinsmore’s death. An autopsy is expected to take place later this week, the coroner’s office said.

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The Crossing said it has no plans to replace the singer in the performance, given the difficulty of the piece. The vocals of “De Materie,” composed in the 1980s, are performed in Dutch.

“We’ll actually be missing a lot of notes,” Nally said.

Led by conductor Reinbert de Leeuw and with a running time of 108 minutes, “De Materie” is scheduled to be performed only once at Disney Hall, as part of the L.A. Philharmonic’s “Minimalist Jukebox” series.

Members of the Crossing resumed rehearsals on Tuesday.

Deborah Borda, president of the L.A. Philharmonic, said in a statement that it was a “profound shock to lose an artist during the preparation of a program.”

“It was a terribly difficult day for all involved,” she said.

Members of Dinsmore’s choir “have chosen to go on with the show and dedicate the performance to his memory,” she said.

Dinsmore, who lived near Wilmington, Del., is survived by Siler, parents John and Lois, and a sister.

His death is believed to be the first time a performer has died at Disney Hall since its 2003 opening.

david.ng@latimes.com, mike.boehm@latimes.com