Before its closure in 2005, the Tabernacle was one of the busiest facilities on the church campus, with more than 500 scheduled events, including broadcasts of the choir's weekly television and radio program "Music and the Spoken Word" and daily organ concerts. World-renowned performers and dignitaries have also graced its rostrum, including 12 U.S. presidents, from James Garfield to John F. Kennedy.

Grow kept no journals of the Tabernacle's construction which began in 1863, 17 years after Mormons settled the Salt Lake valley, Elder Jensen said. But family folklore and Mormon historians say its oval design was inspired by an egg. An account of a conversation between then-church President Brigham Young and Grow was recorded by Young's daughter Clarissa.

"(It) apparently involved Brigham Young slicing an egg lengthwise, rather than in half," he said.

The Tabernacle stands 250 feet by 150 feet and 75 feet tall. It has 44 stone pillars that are 24 feet high.

Engineers reinforced the pillars with steel bars and reinforced the foundations with concrete. Steel boxes and trusses were added to the original wood trusses and secured to the reinforced piers.

In addition, construction crews excavated the building underneath the Tabernacle's pipe organ to make way for new offices, dressing rooms, rehearsal halls and recording studios for the choir.

The main hall also got some fresh paint and other cosmetic work, including new gold leafing on the organ's pipes. Several staircases were relocated to facilitate better movement and the curved ceiling was patched and repainted.

"They tell me the acoustics are as good or better," said Dean Davies, who oversees physical facilities for the church.

Not everyone will be pleased with some of the changes, church officials acknowledge.

The original pine pews have been replaced with locally designed oak ones and a baptismal font where generations of Mormons have been baptized was also removed. Seating capacity in the Tabernacle has dropped by about 1,000.

What wasn't lost was the warmth and intimacy the space provides, said Jackson, who called the Tabernacle "hallowed ground" and said designers tried to use the least invasive methods to upgrade the facility, make physical improvements and add new technology.

Elder Jensen believes Grow would be pleased.

"I think they've honored the integrity of it all," he said. "In the beginning and even today, it was a gathering place ... the Temple and the Tabernacle, in a way, they represent the Mecca of Mormonism and everyone wants to come here."

The Tabernacle's opening coincides with an exhibit at the Church Museum of History and Art just across the street. The exhibit walks visitors through the life of the Tabernacle, from conception to construction and use. It features a life-size model of the huge wooden beams that were cut on a curve and with bolted wooden pegs and recycled iron ox shoes and then lashed with rawhide.

"The Tabernacle is a microcosm of who we are as a community, who we are as a religious faith and 100 years of our history," museum curator Richard G. Oman said.