On the final night of the 2008 Democratic National Convention, Stevie Wonder played his song, 'Signed, Sealed, Delivered.' It became an anthem for the Obama campaign during the 2008 primaries. Tonight President Obama returned to those roots and walked out to give his victory speech to that tune. You can watch Obama giving that speech here.
Or you can watch a particularly funky rendition of that Wonder tune from the 1970s here: