Born at Ilford, Essex, Phyllis Sellick started to play the piano by ear at the age of three and had her first music lesson on her fifth birthday.

Four years later she won the Daily Mirror's "Pip, Squeak and Wilfred" contest for young musicians and was awarded two years' private tuition with Cuthbert Whitemore, subsequently winning an open scholarship to continue her study with him at the Royal Academy of Music.

[7] Composers such as Ralph Vaughan Williams (Introduction and Fugue 'For Phyllis and Cyril') and Lennox Berkeley (Concerto for Two Pianos, premiered at the Albert Hall in December 1948) wrote music specially for them.

After Smith's death in 1974, Sellick continued a long and successful career as a teacher at the Royal College of Music, where her husband had taught.

She continued to work into her 90s, despite her failing eyesight and loss of her playing ability in her left hand following an accident.