Barack Obama's campaign will present a free Jay-Z [ tickets ] concert in Detroit Saturday (10/4) to promote voter registration, according to an Associated Press report. Jay-Z will also play a free show for Obama on Sunday (10/5) at Miami's Bayfront Park.

Monday (10/6) is the last day to register to vote in Michigan and Florida, prompting the last-minute push by Obama, who reportedly has said Jay-Z is one of his favorite musical artists.

The rapper has been promoting the Democratic presidential candidate during his concerts, flashing Obama photos and telling audiences that it's time for a change.

Jay-Z also has designed a T-shirt for sale by Obama's campaign.