The latest Gap ad for Stretch Fall Pants features Claudia Schiffer and another lovely woman walking and riding down a street being showered by falling leaves. The catchy song playing is "September" by Earth Wind & Fire, which can be found on their "Greatest Hits" album. (Thanks to a resourceful member of the Adtunes.com Forums for the info!)

Earth Wind & Fire: Greatest Hits Sony Earth Wind & Fire Amazon Music Price: