Loretta Lynn's Granddaughter Brings Katy Perry to Tears Performing 'Coal Miner's Daughter' on Idol

Instead, Emmy dropped a completely modern-sounding, stripped down original song called "skinny" that was very much telling her own story. She got that gift from her grandmother; the ability to share your story through music.

As the season progressed, she took on the songs of Ingrid Andress, Benson Boone, Bonnie Raitt, Selena Gomez, Blink-182 -- as well as debuting another original song, "Want You." In other words, she was sharing her story and influences on this journey.

That's why Katy Perry felt like she was ready for a full-circle moment.

Now that she's established her own musical identity on the show, it was time to celebrate that iconic legacy and connection, without losing her own artistry. And right away, that was Emmy's approach.

"I know 'Coal Miner's Daughter' like the back of my hand," she told vocal coach Adriana McPhee and associate music director Phredley Brown. "I think I want to do it more like an ode, almost like a way of hugging her."

"I'm Emmy Russell, I'm 24 years old, and I'm proud to be a coal miner's great granddaughter," Emmy declared.

When she hit the stage, the artist who's spent the whole season distancing herself from her famous legacy with original songs and her own unique musical approach, put her distinctive stamp on the classic track.

It was absolutely Loretta Lynn's story, but it was filtered through the life experiences and that lifetime of love that she shared with her family, and with her granddaughter. Emmy stayed true to her own artistic vision while embracing her grandmother's, creating a truly special multi-generational experience.

Through her own tears, Katy told her, "I chose this song not because Loretta Lynn is your grandma. I chose this song because you are Emmy Russell and you can do anything now as Emmy Russell." Neither Luke Bryan nor Lionel Richie were even able to comment through their own emotions.

Another emotional moment in the show came when three alums returned to pay tribute to a member of the American Idol family. Gospel singer and Season 5 contestant Mandisa passed away on April 18 at 47 years old.

Colton Dixon, Danny Gokey and Melinda Doolittle wore matching white to honor her memory as they took on a song she tackled during her run on the show, Mary Mary's "Shackles (Praise You)."

When asked why this song, Dixon replied, "The song sums up her life. I think she came in praising, I think she left praising. We're gonna miss her, but our loss is Heaven's gain."

"I've known her for over 20 years," said Doolittle. "We started off singing background and sessions together, and then she got on 'Idol,' and I cheered for her. Then I came the next season, and she cheered for me. So that is my girl through and through."

Gokey praised the artist for being "a fan of people." He noted that "she was a cheerleader for other people's music," including his own journey, sharing that she was there for him during a down time when he was between labels.

After her time on American Idol, Mandisa slid effortlessly into the world of gospel music, becoming a platinum-selling artist and multi-Grammy winner.

Even as the show was paying tribute to its own legacy, and one of its most famous connections, there was still the business of eliminations to get to. After the Top 8 performed, it was looking like the end of the road for Kaibrienne and McKenna Faith Breinholt.

But, as the winner of the Judges' Choice -- based on how many contestants chose their song from the three options given them by the judges -- Katy was given the power to save one of them. She chose McKenna to round out next week's Top 7, sending Kaibrienne home.

American Idol closes in on its finale in three weeks, and slips to just one episode per week, continuing Sundays at 8 p.m. ET on ABC.