What is the significance of the "bridge" in popular song structure?

The significance of the bridge in popular song structure lies in its role as a contrasting section that adds variety and depth to the song. The bridge typically occurs after the second chorus and serves to break up the repetitive nature of verses and choruses. This section often introduces new melodies, harmonies, or a different lyrical perspective, which enhances the emotional impact of the song. By creating a contrast, the bridge revitalizes the listener's attention and prepares them for the return to the final chorus, where the familiar elements re-emerge. This contrast is essential for keeping the composition dynamic and interesting, contributing to the overall flow and progression of the song.