 In April 1921 Grainger moved with his mother to a large house in White Plains , New York . This was his home for the remainder of his life . From the beginning of 1922 Rose 's health deteriorated sharply ; she was suffering from delusions and nightmares , and became fearful that her illness would harm her son 's career . Because of the closeness of the bond between the two , there had long been rumours that their relationship was incestuous ; in April 1922 Rose was directly challenged over this issue by her friend Lotta Hough . From her last letter to Grainger , dated 29 April , it seems that this confrontation unbalanced Rose ; on 30 April , while Grainger was touring on the West Coast , she jumped to her death from an office window on the 18th floor of the Aeolian Building in New York City . The letter , which began " I am out of my mind and cannot think properly " , asked Grainger if he had ever spoken to Lotta of " improper love " . She signed the letter : " Your poor insane mother " . 
