The 68-year-old Cape Breton singer died Tuesday, prompting condolences from across the country.
Halifax composer and arranger Scott Macmillan says he recalls MacNeil coming to him in the 1980s with a half dozen songs in her head, often asking her band to help put music and arrangement to songs the same day she thought of them.
"I remember her telling me one time songs will come to her when she didn't want them to, almost like getting a headache," Macmillan said in an interview Wednesday.
"She said, 'Oh my God, I've got another song coming.' "
While MacNeil had a propensity to generate idea after idea, her music was remarkably succinct, he said.
"She could say in five words what someone else would have to say in about five paragraphs. She would just get right to the heart of the matter."
Shimon Walt, assistant principal cellist with Symphony Nova Scotia, said the news of MacNeil's death brought back vivid memories of performing with her.
He recalled MacNeil being nervous when she was first invited to perform with the symphony because the orchestra was so big.
"She leaned over to me and said, 'Can I take my shoes off?' " recalled Walt. "It was like someone took a heavy weight off her shoulders (after that). She was completely different. She sang, she was smiling, she was talking to the audience."
Walt said he last saw his old friend at the East Coast Music Awards week in Halifax about a month ago when she performed several songs with Symphony Nova Scotia, including "Working Man."
"When she walked on that stage, it was like a rising sun," he said, his eyes welling with tears. "Every time she started that song, you could feel a squeeze in your chest."
MacNeil was in a wheelchair at the time, Walt said, but insisted on performing on stage with only a cane. He said his last memory of MacNeil was watching her walk off the stage and waving to the musicians.
Prime Minister Stephen Harper offered condolences and referred to MacNeil as one of the country's most popular singers.
"Obviously, a great loss to the cultural scene of Canada," he said.
MacNeil was born in Big Pond, N.S., and during her life discussed the self-confidence issues she battled because of her weight. She loved to sing as a child, despite her shy disposition and a cleft palate that required surgery.
Her publicist says she died in hospital in Sydney, N.S., from a recurring infection. Funeral arrangements were pending on Wednesday afternoon.
Nova Scotia Premier Darrell Dexter issued a statement praising the three-time Juno Award winner for her passion and consistent message that dreams can be achieved.
"Despite her worldwide success, you felt like you could be her friend," Dexter said.
Federal Labour Minister Lisa Raitt, a fellow native of Cape Breton, said MacNeil's rise from being a single mother playing small folk venues to international stardom was an inspiration to her.
"Did I wake up this morning and cry? Yup, I did. It's a sad day for all of us," she said. "Hopefully we'll still be able to hear her music on and on and on."
The Cape Breton Regional Municipality lowered flags to half-mast to pay tribute to MacNeil.
Brookes Diamond, her former manager, recalled her as "a poet."
He said MacNeil used the judgments others made about her physical appearance for her own artistic expression.
"It could be a challenge to make your way around like that. But that influenced her writing and it gave her a sense of the pain of others," he said.
Diamond said he first encountered MacNeil after booking her into a Nova Scotia folk festival in the early 1980s.
"I happened to be driving through the field where she was performing and heard this voice coming through the mist and I was transformed," he said.
"I'd never seen anybody like that before."