 At the same time, Slaughter composed incidental music for plays, including those produced at the St. James's Theatre, while he was employed as the musical director there, including, in 1890, Walter Frith's "Molierè" and Quinton and Hamilton's "Lord Anerley"; in 1891, Haddon Chambers's "The Idler"; and in 1892, Oscar Wilde's "Lady Windermere's Fan" and "Donna Luiza" (with Basil Hood as librettist).Slaughter's breakthrough success came in 1895 in collaboration with Hood with the musical comedy "Gentleman Joe, The Hansom Cabbie" as a vehicle for the low comic Arthur Roberts.Bernard Shaw dismissed the score in "The Saturday Review"