His last solo recital at London's Royal Festival Hall was attended by HM The Queen Mother.

Vallier's aunt and principal teacher was Mathilde Verne, a pupil of Clara Schumann, and through whose piano school in London passed the young Vallier as well as the pianists Solomon and Moura Lympany, and even socialite Lady Elizabeth Bowes-Lyon (later Queen Elizabeth The Queen Mother).

Vallier gave his first solo concert at the age of eight, and was something of a child prodigy giving recitals in the South of France.

He also brought classical music to children in parts of the country where live performances were rare in the 1940s and early 1950s at schools for the WEA.

These and some of Vallier’s detailed writings appeared in his Oxford University Press Chopin Edition (1986).

[citation needed] A Chopin Recital at New York’s Carnegie Hall in 1983 was particularly well received, and Vallier was to return to tour the States the next year.

Despite all odds, he returned again to the concert platform, in a solo recital in 1986 at London's Royal Festival Hall, attended by HM The Queen Mother.