America's Got Talent determined its final four seventh-season Top 24 semifinalist acts during Wednesday night's live broadcast of the NBC reality talent competition series.

Andrew De Leon, a gothic self-trained opera singer; Sebastien "El Charro de Oro," a young mariachi singer from San Antonio, TX; and Todd Oliver, a ventriloquist and dog act from Branson, MO, were revealed to have finished as the Top 3 vote-getters after Tuesday night's performance show which featured 12 acts performing in a special "wild card" quarterfinals round for home viewer votes, automatically earning them a spot in America's Got Talent's seventh-season semifinals.

While Sebastien "El Charro de Oro" and Todd Oliver were both Top 48 quarterfinalist acts which had previously failed to advance out of their group during America's Got Talent's earlier seventh-season quarterfinal rounds, Andrew De Leon had never made it through to the quarterfinals.

America's Got Talent host Nick Cannon also revealed that Ben Blaque, a crossbow act from Branson, MO; Bandbaz Brothers, a pair of performing acrobats; Horse, a daredevil from Harrisburg, PA; Jake Wesley Rogers, a singer and guitarist from Ozark, MO; Cristin Sandu, a balancing act from Las Vegas, NV; Spencer Horsman, an escape artist from Baltimore, MD; and Jarrett and Raja, comedy illusionists from Las Vegas, NV, had received the seven lowest home viewer vote totals from the performance show and would not be advancing to the semifinals.

The announcements then left America's Got Talent judges Howard Stern, Sharon Osbourne and Howie Mandel with the task of deciding which of the two acts that had received the fourth and fifth highest vote totals -- Lindsey Norton, a solo dancer from Tampa, FL, or All That!, a male clogging group from Myrtle Beach, SC -- who were only separated by half of a percent in the results, should become the fourth act to advance to the semifinals.

Howard voted to send All That! through to the next round, and then Howie voted for Lindsey to advance. As a result, Sharon became the tie-breaker vote and had to choose between two of the acts she had selected to be in the "wild card" show to begin with. After a little hesitation, Sharon decided to allow All That! to move forward in the competition.

Now that America's Got Talent's Top 24 semifinalist acts have been determined, the semifinals will begin on Tuesday, August 28 when 12 acts will perform and attempt to continue advancing in the competition.