The third in a series of free concert events headlined by rapper Jay-Z, designed to drive last-minute voter registration and encourage attendees to get involved in Democratic presidential candidate Barack Obama's campaign, was canceled moments before it was scheduled to begin Monday night, leaving thousands of disappointed fans inside Miami's Bayfront Park.

A spokesperson for the Obama campaign told MTV News on Tuesday (October 7) that the "event that was supposed to take place [Monday in Miami] did not happen," after Jay-Z said he "was sick." The nature of the rapper's illness had not been officially disclosed at press time, but various online reports suggest he was suffering from a throat ailment. The Obama spokesperson added that "Sunday's event [which was also hosted at Bayfront Park and featured a performance by Wyclef Jean] went on and was successful."

Jay-Z, an outspoken supporter of Obama's presidential campaign, announced last week that he'd be anchoring a pair of free concerts — the first, scheduled for Cobo Arena in Detroit on Saturday, and the second, to take place in Miami the next evening — and that the purpose of the events would be to promote both Obama's campaign and voter registration. The timing of the events wasn't coincidental: Voters in both Florida and Michigan had until October 6 to register to vote.

Monday night's event was scheduled following the success of Sunday's concert, the Obama spokesperson said. Jean and Rick Ross were also slated for the bill, and initially, the concert's organizers reportedly hoped the show would go on without Jay, ultimately to no avail. It remains unclear whether Jay-Z will reschedule Monday night's event, but that seems unlikely since the voter-registration deadline has passed.

A spokesperson for Jay-Z had not responded to MTV News' requests for comment at press time.

According to the Miami New Times, Jay-Z kicked off Sunday night's set with a disclaimer: "I'm a free American citizen stating my f---ing opinion!" the rapper declared, before offering his endorsement of Obama. Jay-Z's set included "Can I Get A...," "Can't Knock the Hustle," "Roc Boys," "Big Pimpin' " and "Hard Knock Life."