I grew up with parents who loved R&B and soul music. And as a result, Earth Wind & Fire was always playing in my house. It was the soundtrack to everything from our Saturday chores to our family cookouts. And “September” was a song that was guaranteed to get everybody dancing.

The song was written in 1978 by EWF band members Maurice White and Al McKay along with songwriter Allee Willis. But it is a groove that will rock family reunions and wedding receptions from now until eternity. And while almost everyone can sing along with Maurice White on the famous line, “Do you remember, the 21st night of September?,” not everyone can agree on what the hell he was actually talking about.

Some people think the reference to September 21st is a nod to the change of seasons. And considering that the first day of fall is right around the corner, it’s actually not a bad guess. But unfortunately, the truth is not that deep. In fact, Allee Willis, one of the song’s co-writers says they chose the date because they liked the way it sounded. “We went through all the dates: ‘Do you remember the first, the second, the third, the fourth … ‘ and the one that just felt the best was the 21st,” she said in a 2014 interview with NPR.

And if you’re anything like me, you can’t resist belting out the song’s chorus, especially the part that goes” Ba-dee-ya, say, do you remember? Ba-dee-ya, dancin’ in September.” But if Willis had it her way, those words would have never made it into the song. During the songwriting process, Maurice White used the words as melodic placeholders. And in her NPR interview, Willis admits she fought White to have the silly syllables replaced with real words.

“And finally, when it was so obvious that he was not going to do it, I just said, ‘What the f*** does ‘ba-dee-ya’ mean?’ And he essentially said, ‘Who the f*** cares?’” she says. “I learned my greatest lesson ever in songwriting from him, which was never let the lyric get in the way of the groove.” Thank goodness she didn’t get her way.