He had his first big stage success with Ages Ago (1869), a short comic opera with a libretto by W. S. Gilbert, for the small Gallery of Illustration; it ran well and was repeatedly revived.
In addition to Gilbert, Clay's librettists during his 24-year career included B. C. Stephenson, Tom Taylor, T. W. Robertson, Robert Reece and G. R. Sims.
The historian Kurt Gänzl has called Clay "the first significant composer of the modern era of British musical theatre",[1] but even his most successful stage works were soon eclipsed by those of Gilbert and Sullivan.
[3] Through the influence of Lord Palmerston, Clay secured a post in HM Treasury,[4] and was for a time private secretary to Benjamin Disraeli, who presented him at a court levee in 1859.
[4] In his free time he studied music with Moritz Hauptmann in Leipzig, and composed what his biographer Christopher Knowles calls "songs and light operas for the drawing rooms of high society".
[2] With his fellow Treasury clerk B. C. Stephenson as librettist he wrote three one-act operettas for amateurs: The Pirate's Isle (1859), Out of Sight (1860) and The Bold Recruit (1868).
[4] The Era commented on the second of these: "The composer is an amateur, but he has shown a dramatic power and a skill in instrumentation that would justify him in entering the lists with professional musicians".
[7] Clay had a modest operatic success with a one-act operetta, Court and Cottage, to a libretto by Tom Taylor, produced at Covent Garden in 1862 as an after-piece to Meyerbeer's Dinorah.
[14][n 4] In 1869 came Clay's first substantial theatrical success, the "operatic entertainment" Ages Ago, written for the German Reeds at the Royal Gallery of Illustration, with a libretto by W. S.
[24] The last of these, given at Covent Garden was a spectacular production that ran for some eight months and attracted highly favourable notices for Clay and his fellow composer, Jules Rivière.
[25] Foreseeing, and not relishing, a long period of Conservative government after the party's election victory in February 1874, Clay resigned from the Treasury.
This successfully toured the provinces, with the composer conducting and Santley starring as Pincione; it was given at the Charing Cross Theatre, London, during the winter season of 1874–75.
The Times's later comment that the piece was "probably surpassed by no modern English work of the kind for gaiety and melodious charm"[28] was not generally shared: a recurring theme in reviews was that Clay's music was musicianly and pleasing but not strikingly original or memorable.
[30] When it was revived in London in 1881 The Times commented that the piece had not appealed to audiences in 1876, "accustomed to a more broadly humorous style of extravaganza" and hoped that by 1881 public taste had become more cultivated under the influence of Gilbert's other comic operas.