Perry, who has been campaigning for Obama wowed the audience with her rendition of popular songs including "Teenage Dream" and Al Green's soul hit "Let's Stay Together" before turning over the crowd to Obama with a thumping bass drum version of "Firework".
The former gospel music artist told the huge crowd gathered at the Las Vegas rally to vote early and make their mark.
Perry is one of the most popular artist on Twitter.with over 29 million followers
, ranking second to Lady Gaga who is racing to hit the 30 million mark.
The 28-year-old young-looking singer who turned 28 Wednesday, wore a tight white dress
imprinted like a ballot with the names of Obama and Biden marked in black.
In his speech before the huge outdoor crowd, Obama said
"I believe in you. I need you to keep believing in me," as he urged the voters to help him with his reelection bid.
Less than two weeks before the election, Obama is running neck and neck with Republican candidate Mitt Romney.
In their three-debate series, surveys reveal Romney won the first debate while Obama took the lead on the last two debates with a small margin.