Eustis first drew attention as a theatre composer with the 1879 musical Sancho Pedro, with a book by Charles Felton Pidgin, staged at the Gaiety Theatre on Broadway in 1879.
[2] This was followed by the musical Penny Ante; or The Last of the Fairies, with a book and lyrics by Jeff S. Leerburger and premiered at Broadway's Fourteenth Street Theatre on June 9, 1884, It featured the actor Charles H. Drew performing the title heroine in drag.
[3] He wrote music for the 1890 musical Blue Beard, Jr. which was a tremendous success when it premiered at the Grand Opera House, Chicago;[4][5] ultimately touring to Broadway's Niblo's Garden.
[6] Eustis composed music for two Broadway musicals based on classic fairy tales: Mother Goose (Fourteenth Street Theatre, 1899) and Little Red Riding Hood (Boston Museum, 1899; and Casino Theatre, 1900).
[11] Eustis died at the age of 53 on March 28, 1912, in Toronto, Canada.