Though this song was never released as a single, it hit the US Billboard Top Tracks chart (based on airplay alone) at #4 anyway. Just one more testament to how badly the fans would miss Led Zeppelin, knowing that this album was their swan song (barring reunions).
Led Zeppelin is one of the most famous bands in history to have never gotten a #1 hit single on the US Hot 100. They only mustered one Top 10, with 1969's "Whole Lotta Love
." Only five other Zeppelin songs scored in the top 40!