Like so many young singers and songwriters, Caitlin Crosby had a Hollywood dream.

"Just a little bit prettier, just a little more popular, just a little richer," say the lyrics to one of her songs.

Click here for more information on donating keys to The Giving Keys.

It turned out, though, that the key to her success was not of the musical kind.

A simple hotel key that she wore on a chain around her neck while performing in New York has inspired a line of jewelry called The Giving Keys in Los Angeles.

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Ranging from rings to necklaces, they've been worn by celebrities like actors Ryan Gosling, Selena Gomez, Zac Efron and Eva Longoria. Even Arianna Huffington.

In 2008, Crosby said, she asked a locksmith to engrave a hotel key with some inspirational words. She then wore the key as a necklace. When fans showed interest, she started taking old keys, engraving them and selling them on tour. The keys sold out every time.

"I came up with this whole pay-it-forward concept," she told ABC News.

Then one day, while walking in Hollywood, she met a homeless couple, a man and woman.

"I asked them to go to dinner," she said. "[The woman] said, 'I like making jewelry,' and I had my aha moment."

The pair started working for Crosby. She said they'd saved enough money to get an apartment as well.

Crosby said she now found workers through partnerships with Los Angeles-area organizations and transitional programs, which screened potential employees for the company.

The Giving Keys has more than 20 employees, including four in the process of transitioning from a life on the street.

"We've gotten a ton of people off the street so far," she said.

ABC News' Eric Noll contributed to this story.