Taylor Swift will pay tribute to a young cancer victim with a special song at the Stand Up To Cancer telethon in the US.
Ronan is dedicated to a four-year-old boy who of neuroblastoma last year.
Taylor wrote the song after reading the blog of Ronan's mother, Maya Thompson, who is credited as a co-writer.
According to a person familiar with the show, the song has never been performed in public.
After the telethon, it will be available on iTunes, and all proceeds will go to cancer-related charities.
Stand Up To Cancer takes place on Friday (September 7) and will air on all the major networks and cable channels in the US.
Besides Taylor, it will feature celebrities including Tom Hanks, Julia Roberts, Gwyneth Paltrow and Justin Timberlake.