English singer-songwriter and pianist who has announced that he will perform his last ever UK show at Glastonbury in 2023 (5,4)
I believe the answer is:
elton john
(Other definitions for elton john that I've seen before include "Singer/pianist/composer" , "Your Song singer" , "Flamboyant singer and pianist" , "English composer, singer and pianist, born 1947 and named Reginald Dwight" .)