Surely sparking the song's gain? Its opening lyric: "Do you remember the 21st night of September?"
"September" also debuts at No. 7 on R&B Streaming Songs with 8.5 million U.S. streams, up 100 percent.
"September" saw its sharpest gains on, of course, Sept. 21, when it sold 5,000 downloads, a 788 percent increase from the day before. The track also logged 4.1 million on-demand U.S. streams (audio and video combined) on Sept. 21, up 386 percent from 847,000 the previous day.
Playing into the fun, Earth, Wind & Fire's Twitter account posted a poll on Sept. 21 asking followers simply, "Do you remember?" Of the half-million users who responded, 88 percent replied "yes."
The disco track is one of Earth, Wind & Fire's biggest chart hits. It peaked at No. 8 on the Billboard Hot 100 (dated Feb. 10, 1979) after spending a week at No. 1 on Hot R&B/Hip-Hop Songs (Jan. 13). It became the group's fourth top 10 (of seven total) on the Hot 100 and its sixth No. 1 (of an eventual eight) on Hot R&B/Hip-Hop Songs.