Sturgill Simpson is among the many artists mourning folk icon John Prine following his death on Tuesday (April 7). In a soul-bearing Instagram post, Simpson reflects on his relationship with Prine, whom Simpson says reminded him of his grandfather.

"There are sometimes people in this life that you meet, seldom and few and far between it would seem, whose souls are so good and pure and beautiful that when they leave it seems if only for a brief while that everything else good and pure and beautiful in this world just left along with them. It blows you apart leaving everyone to see you broken," Simpson writes. "But then you come out of the woods and the funk to see the signs of spring all around you and remember the joy and love they put into the world by always giving so much of themselves and you suddenly see them everywhere."

Indeed, Prine -- who died on the day of a pink supermoon -- left behind a legion of adoring fans, many of whom are famous themselves. The legendary songwriter was known for his incredible way with words, but also for his friendships with other artists, with whom he often collaborated.

Simpson was among those artists: In 2018, as Prine was releasing what would be his final album, The Tree of Forgiveness, Simpson appeared in Prine's "Knockin' on Your Screen Door" music video, and joined Prine for a late-night TV appearance. Simpson's tribute to Prine is accompanied by a photo of the pair riding a motorcycle together.

Simpson admits that "[t]here is so much I’ll never get to say now" that Prine has died. "There is so much I never said only because I didn’t want to bother you with it. After all you never asked to be 'John Prine,'" Simpson writes.

"I will miss the tours ... I will miss our lunches ... I will miss you listening to me b---h and complain about all the things you understood all too well and making me feel better sometimes by just sitting there saying nothing," Simpson continues. "I will miss catching flies in mid-air with my hand just to make you laugh ... I will miss showing up to the office and knowing I'd just missed you there by finding my drums upside down ... I will miss your corny-ass jokes."

Prine was 73 years old when he died, after contracting the novel coronavirus (COVID-19) in late May. He is survived by his wife of 24 years, Fiona, three sons, a daughter-in-law and grandchildren.

"I will miss you. Every day," Simpson concludes. "So long old man. You will always be loved."

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