Frank J. Metcalf's "American Writers and Compilers of Sacred Music" (originally published in 1925, reprinted in 1966) has a long entry for Henry Wellington Greatorex (pp.256-62) with a picture.H.W.'s father was, indeed, Thomas Greatorex, organist of Westminster Abbey. Thomas was quite famous in his day and you should be able to find a lot about him. (Try the Dictionary of National Biography where there is a longish entry)H.W.'s grandfather was Anthony Greatorex, who was organist at the parish church of Burton-on-Trent, Staffordshire, for some 43 years during the 18th and early 19th centuries. Anthony came from North Wingfield, Derbyshire. He was born about on 15 July 1730 and died in Burton-on-Trent on 19 Nov. 1814.Prior to coming to Burton, he was organist at St. Martin's church in Leicester from 1765 to about 1777, and went to Burton from Leicester.Besides being an organist, Anthony also played bassoon in many concerts in Leicester and Burton during the later 18th and early 19th centuries.