Jackie Chan and Chris Tucker chatted with ET on the set of 'Rush Hour,' explaining how they blended action and comedy for the 1998 classic. In behind-the-scenes interviews, the martial arts icon joked about how much his co-star improvised while filming. The 'Friday' star recalled teasing him while singing their 'War' duet, calling out Jackie, who also boasts a prolific singing career overseas, for 'trying to sell some albums' off their memorable scene.