For Dillingham, performing in Dunhuang and engaging in cultural exchange today means "actively participating in the continuing story of the modern Silk Road".
One of his best-known original songs inspired by the ties between Gansu and Oklahoma is Old Friends, written after years of performing for Chinese audiences.
"Old friend, won't you sing with me? Sing with me, drink with me, share with me. I'll soon be gone, but I'm coming back again," the lyrics say.
Whenever he discusses the song, Dillingham almost instinctively begins singing the lines himself. He once performed the song with the Lanzhou Symphony Orchestra, incorporating the ruan, a traditional Chinese plucked-string instrument.
"The song reflects how friendships rise and fall, ebb and flow," Dillingham explains. "But in the end, we remain old friends and continue looking toward the future together."
He still remembers a performance in Qingyang in 2017 celebrating the sister-city relationship between Qingyang and Edmond, Oklahoma.
After the concert, an elderly Chinese woman walked onto the stage. She spoke no English, but simply took his hand.
"She just looked at me with tears in her eyes," he recalls. "At that moment, I could tell she was trying to say, 'Thank you for the concert, thank you for the music, thank you for being with us.' We locked eyes, and I felt so much warmth and appreciation. It's something I will always remember."
After decades of traveling between China and the United States, Dillingham believes people-to-people exchanges remain essential.
"For many Americans, China is still a distant and unfamiliar place," he says.
He believes music has a unique ability to narrow that distance. "Music can speak directly to the heart and soul. No matter where people come from, sharing music is still one of the best ways for us to understand each other."
Dillingham hopes his own experiences will encourage more Americans to visit China themselves. "I hope people can learn from what I've experienced in China and feel inspired to discover it on their own. The people here are incredibly welcoming and hospitable."
Reflecting on four decades of ties between Gansu and Oklahoma, he sees both history and responsibility in the relationship.
"What comes next is really up to us," he says. "Together, we have an opportunity to shape China-US relations in the decades ahead. I prefer to envision a future where we continue singing and sharing together, just as old friends should."
"It's our honor to continue nurturing the friendship not only between Oklahoma and Gansu, but also between the United States and China," he says.
Looking ahead, he adds that he hopes to return to China this year. "My band keeps asking me for updates. We always have such an amazing time, sharing our music with Chinese audiences."