[1] He was the son of Henry John Gardiner, a successful entrepreneur who made a considerable fortune in the drapery wholesale business in Bristol and London.

[3] Between his conventional education at Charterhouse School and New College, Oxford, where he obtained only a pass degree, Gardiner was a piano student at the Hoch Conservatory in Frankfurt, where he was taught by Iwan Knorr and Lazzaro Uzielli, who had been a pupil of Clara Schumann.

[17] Gardiner's most important work, possibly, was his promotion of the music of contemporary British and colonial composers, particularly through a series of concerts he personally financed at Queen's Hall London in 1912 to 1913.

The composers represented included Arnold Bax, Frederic Austin, Gustav Holst, Percy Grainger, Roger Quilter, Cyril Scott and Norman O'Neill.

Gardiner was very generous with his personal fortune, paying for a private benefit performance of The Planets for Holst in 1918 and purchasing Frederick Delius's house at Grez-sur-Loing to enable him to continue living in it at the end of his life.