On Tuesday, delivering the penultimate performance of the live finals, fans learned even more about Lee and fell even deeper in love with his inspirational story and his incredible voice.
Life hasn't been a smooth road for Lee, or his family. The talented pianist was only a few months old when doctors discovered he was blind, and it wasn't long after that he was diagnosed with autism.
But, as he explains in his finals pre-taped package, music has meant everything to him.
"Music makes me feel better," Lee explained in the interview. "I tell people I love them through my songs. I speak to them."
When asked if he's scared about doing a good job at the finals, the musician explained that he feels safe because he knows how much love he has in his life.
"I'm happy-nervous," Lee said. "But my family is always there for me. My mom is always there for me. Thank you, mom, for all the help. My dreams are coming true!"
For his finals number, Lee delivered a heartbreaking and powerful rendition of Freya Ridings' "Lost Without You," which showed, yet again, the power of his vocal talent and really revealed how well he can communicate emotions through music.
Lee's performance was met with a standing ovation from every single person in the audience, and the judges had a hard job maintaining their composure as they fought back tears to give their effusive feedback.
However, it was Simon Cowell who seemed to be struck the hardest by the performance, as the outspoken and sometimes acerbic judge struggled to find the words to express how much he loved Lee's song.
"One of the most beautiful things I've ever, ever heard," Cowell said, in awe, adding, "That was as good as I've ever heard."
The audience clearly agreed as they began to chant Lee's name while he smiled uncontrollably on stage and basked in the support.
Cowell spoke with ET's Denny Directo backstage after the show, and he reiterated his appreciation for Lee's talent.
"Kodi has this ability to put you on edge before he sings. There's like the longest pause ever... and then he does it it," Cowell said, referring to the long pause Lee is known for taking before each of his performances. "He's just got this unbelievable ability to know when to bring it. And the song choice was beautiful."
To see if Lee ends up winning it all, fans will have to tune in to the America's Got Talent season 14 finale and results show on Wednesday at 8 p.m. ET/PT on ABC.