Mandy Harvey's musical journey on America's Got Talent has to be one of the most inspiring stories in the show's history -- and on Tuesday's live quarter-finals episode, she got another chance to show just how incredible she really is.
The powerful singer-songwriter grew up pursuing music as her passion and career, but fate threw a roadblock in her path when she began to lose her hearing when she was 18, due to a connective tissue disorder.
WATCH: 'America's Got Talent': Two Inspirational Singers Steal the Show -- and One Gets the Golden Buzzer!
"When I lost my hearing, music died. I lost my way of communicating. And my parents were the ones who encouraged me to find music again," Harvey said in a pre-recorded package before her live performance at the Dolby Theater in Hollywood on Tuesday. "I was told for such a long time that you had to have hearing to enjoy music. But I've found that music was meant to be felt. Feeling everything move -- feeling the song through the floor, feeling my voice."
After losing her hearing, Harvey had to re-learn how to sing and how to trust her pitch. Her emotional performance during the audition round got her the Golden Buzzer, and this time, she came back even stronger.
WATCH: Johnny Manuel Wins Over Simon Cowell With 'Diva' Performance of a 'Dreamgirls' Song
Standing by herself with nothing but her ukulele, the 29-year-old entertainer poured her heart out on stage with a beautiful, original ballad titled "Mara's Song," which she wrote for her close friend's wedding.
Flawlessly hitting every high note and masterfully playing the small, delicate ukulele, Harvey perfectly demonstrated her stunning talent at feeling the music, and making everyone else feel it as well.
The touching performance earned a standing ovation from the entire audience, and brought a smile to the faces of all the judges, some of whom were moved beyond words.
Judge Simon Cowell was the first to give feedback and he had trouble finding the right words to really express how much he appreciated and enjoyed her song.
"There is so much I could say to you -- so much I want to say," an emotional Cowell began. "But your music, and you, says it all. All I'm gonna say is you are and you will make a difference. That was stunning."
WATCH: 'AGT': 13-Year-Old Singer Gets Golden Buzzer After Touching Audition Gave Judges 'Goosebumps'
For Heidi Klum, the best part of Harvey's performance was "how raw and how real and how honest" the whole thing felt.
"There was no backing track, there was no production around it. It was just you, your beautiful voice, your ukulele, and it was very powerful," she shared.
Mel B was equally effusive with her reaction, praising the singer for her impact and her influence on others who look to Harvey as an inspiration. "You make the impossible, possible," the former Spice Girls star said. "You're like a miracle worker, and you've literally taken me on an emotional journey."
WATCH: 'AGT': See Which Amazing Acts Made It Through the Judge Cuts Rounds
During the AGT audition rounds, Harvey took to the stage with her ukulele -- while also accompanied by a guitarist and a keyboard player -- and performed a soul-stirring original ballad called "Try," which told the story of her emotional journey, and particularly touched Cowell, who immediately forwarded her to the live rounds.
"When Simon hit the Golden Buzzer for me, it just meant so much," Harvey shared in the pre-taped package. "He was looking at me as a musician and not just as that broken person. Everything is very different from my childhood picture of who I was going to become, and I'm really glad that it's different."
To see if Harvey makes it into the semi-finals, tune in to the America's Got Talent results show on Wednesday at 8 p.m. ET/PT on NBC.
Check out the video below for a look at Harvey's personal and beautiful AGT audition that earned her the Golden Buzzer.