As Rihanna was on the cusp of shedding her innocent island gyal image and embracing her Good Girl Gone Bad persona (short crop haircut, steamier ensembles and all), she gifted pop culture the rainy day pick-me-up "Umbrella."

Penned by singer-songwriter The-Dream, the hook for the 2007 No. 1 hit -- which made Billboard's Best Choruses of the 21st Century list -- featured young Riri offering protection from an emotional storm, singing, "When the sun shines, we shine together/ Told you I'll be here forever/ Said I'll always be your friend/ Took an oath that I'm a stick it out till the end/ Now that it's raining more than ever/ Know that we still have each other/ You can stand under my umbrella." 

Despite its weather-y peg, The-Dream doesn't cite a specific torrential downpour or earth-shattering breakup that inspired the song, which also featured a Rain Man-referencing Jay Z. "It was a typical day and no one really influenced the record per se," he tells Billboard over e-mail. "I felt in my heart at the time that I needed a friend like this. I wanted to also be that person for someone else." 

The master lyricist (born Terius Nash) did, however, made the metaphors... rain. "It took maybe 15 minutes to get out the song, it began like a rap freestyle and it just never stopped pouring, metaphor after metaphor," he notes. "I was in a zone and in a feeling that wasn't going to end until I finished what I had to say."

As for that mandatory chant on the hook where Rihanna repeats "ella, ella, ella, eh, eh, eh," The-Dream says it was just an old-fashioned way of incorporating an age-old studio technique into the track. "The 'Ella' part was a play on reverb," he says. "Back in the day we couldn't afford the good reverb program so I started repeating the phrases to make it sound like it." 

He also considers the "Umbrella" hook a part of his personal Hall of Fame of choruses, but also calls the hook for the 2005 Young Jeezy hit "Soul Survivor" featuring Akon his favorite. Even 10 years later, "Umbrella" remains a life-changing milestone for The-Dream. "It's deff one of my favorite hooks," he adds. "It changed everything after that and I'm grateful for it."