Duffy has shared her first update with fans after revealing she was drugged and raped and held captive by an attacker.
The 35-year-old singer told her followers she feels "freer" after speaking out and will be giving more information soon.
She also said she was finding it difficult to talk about what happened, writing: "It's harder than I thought."
Duffy initially shared news of the ordeal in a statement on Instagram last month.
Returning to the platform, Duffy addressed her statement to DJ Jo Whiley - and shared her first new music in a decade.
The singer said part of her reason for sending the track was due to the coronavirus outbreak, which is affecting people around the world.
Duffy wrote: "Hope you are well and keeping safe. You may have read the words I wrote a few weeks back, I do feel freer.
"Tried to follow up with a spoken interview, but it's harder than I thought, I will follow up in writing soon."
She said the song - Something Beautiful - was "to play people on radio during these troubling times, if you like the song of course. If it lifts spirits".
A love song, it begins with the words: "Bring me something beautiful, bring me something divine."
The Welsh singer - whose full name is Aimee Anne Duffy - said her management team didn't know anything about her sharing the track, but promised: "They won't be mad, they are lovely people."
She said she doesn't intend to release the song, but hoped it would raise the spirits of "people if they are at home, on lockdown".