If you ever happen to get into an argument with someone about what the most chilled out song of all time is, this is your trump card. "Chilled out" might not be a description that would satisfy an academic, but in this case the term applies.
Picture in your mind a summer's day. The sun is blazing and it's hot enough that you're starting to sweat. The action around you in the city just makes the environment all that more unbearable. And then a cool breeze hits, sending shivers down your spine, the ultimate refreshment. That's what Summer Madness by Kool and the Gang is.
Other people realized this long before me, and so Summer Madness has been sampled a few times. This isn't a comprehensive list of the songs that have sampled it, just a few notables.
Most people might recognize that it's sampled in Summertime by DJ Jazzy Jeff & the Fresh Prince. Speeding up the bassline and chopping up the synth wail make the song danceable, and still everytime the synth line moves up an octave the air gets colder. Curiously enough, this song wasn't produced by DJ Jazzy Jeff; I bet he wishes he did it, though.
My personal favorite song that samples Summer Madness is DJ Premier in Deep Concentration. I've heard DJ tracks, and this is still the most amazing to me. I don't even DJ and I'm playing air DJ, scratching and hitting the fader when this song comes on. Even though I've never been there, this song feels like NYC traffic at night.
The most recent sampling I've come across is by Pete Rock for a song called Midnight And You that's shown up on Pete's second instrumental album, The Surviving Elements. Using only the bassline, the Chocolate Boy Wonder crafts his own synth line it all comes together for another relaxing song.