Pioneer Day celebrates those who came before, who broke new ground and made untold sacrifices.

"As President Hinckley used to say, July 24 is ours and ours alone. We should celebrate it and give it all we've got," says Mormon Tabernacle Choir president Mac Christensen.

That's exactly what the choir, the Orchestra at Temple Square and their invited guests, the Osmond family, will be doing this weekend, with two concerts in the Conference Center.

"We are the luckiest people in the world," Christensen says, "to be able to celebrate with this choir, this orchestra, this great pioneering family, these great people."

Those sentiments are echoed by choir director Mack Wilberg. What better way to celebrate the pioneer spirit, he asks, than through music? It is a great honor, he says, to have the Osmonds join the celebration. "They are pioneers in the field of entertainment. Plus this concert concludes their worldwide 50th anniversary tour. It's so appropriate to end it here, where it all began for them."

As for the Osmonds, these concerts will mark a bittersweet milestone. "This will be our last performance on stage with the whole family," says Merrill. "So we feel a bit overwhelmed. To have it end here, with the Mormon Tabernacle Choir — there couldn't be a better way."

The Osmond Brothers — Alan, Wayne, Merrill, Jay and Jimmy — as well as their two older brothers Virl and Tom, were in town for a rehearsal with the choir and orchestra Tuesday night. They will be joined by Donny and Marie later in the week.

The concert will feature pioneer songs and songs of the frontier by the choir and orchestra. The Osmonds will perform a couple of sets featuring some of their hit songs and fan favorites, which will incorporate snippets of home movies and other video of their careers.

It's a lot of fun for the choir to have the Osmonds join it, says Wilberg. "We've sung with Sting and with the Oak Ridge Boys, so it's not entirely new ground for us. But it showcases the versatility and spirit of the choir. And you have to admire the Osmonds and what they have done. They've been together many, many years."

That fact surprises the Osmonds as much as anyone. "When we were kids they told us we'd never make it in show business; we were too clean-cut," says Alan. "Then after we were on TV, they said we'd never have hit records, because we were too television-oriented." But the Osmonds proved the world wrong at every step. "When we were kids we were told that we would open doors. Our whole mission has been to share what family is all about," he says.