I recall a well-known conductor once telling me that one of the hardest things to do is to write about music that one has never heard: and with this I totally agree, having tried it a number of times. However, what can be interesting is to read tantalising accounts of music that has disappeared from the repertoire – and because the score/manuscript has been lost, will never be heard. The main justification for this is twofold – firstly it allows the listener to gain more contextual knowledge about the composer in question and secondly it may spur someone to look for and maybe even discover the ‘lost’ work. Who knows?
Charles Villiers Stanford’s Festival Overture was composed around 1870  and was given its first performance in the Shire Hall at the Gloucester Three Choirs Festival on 6 September 1877, conducted by Charles Hartford Lloyd. It was subsequently performed at the Crystal Palace on 17 November of that year, conducted by August Manns. The manuscript has been lost. The reviewer in the Musical Standard wrote:-
“The performance of the seventh Saturday concert contained, as usual, some works which had not been previously heard at Sydenham, the novelties being C[harles] Villiers Stanford’s Festival Overture (written for the Gloucester Festival lately held ), the scene of Isolde’s death from Wagner’s Tristan und Isolde, and the ballet music from Mose in Egitto ... 
Mr Stanford’s overture is rather disappointing to those who watch the career of this rising young English composer, not much on account of any lack of constructive skill, but simply because inventive power appears, to a great extent, to be wanting. Mr. Stanford masters the technicalities of his task with ease, and his method of scoring proves him to be quite at home in all matters appertaining to the treatment of the orchestra. But the themes of his overture do not display much originality, nor are they attractive in themselves, which leaves all the commendation we can bestow upon the production for the ingenuity it undoubtedly reveals. The tone of the compositions hardly appears to warrant the fact of its being written for a festal occasion; but this, after all, is a mere matter of opinion.”
CRYSTAL PALACE CONCERTS Standard 26 Nov. 1877
Jeremy Dibble gives some interesting information about this work in his book Charles Villiers Stanford: Man and Musician. He notes that Hubert Parry had gone to Gloucester especially to hear this work. In his diary he [equivocally] wrote ‘’It is better than the ordinary run of such things well enough scored; with plentiful use of brass- and figures of little significance much used, rather made up I think altogether.’ CHHP Diary 6 September 1877.
Dibble also observes that the analytical notes written by George Grove suggested that ‘the spirit, rhythm, and power over the Orchestra which characterise this interesting work, augur well for Mr. Stanford’s artistic future, and encourage us to look for more orchestral works from his pen’.
Certainly this last wish was granted, and we are fortunate in having the vast majority of Stanford’s orchestral compositions available on CD or MP3.
 Jeremy Dibble suggests that this work was composed c. 1870 whereas Paul Rodmell concludes that it was in 1876.
[2 Mose in Egitto (Moses in Egypt) is a three-act opera written by Gioachino Rossini to an Italian libretto by Andrea Leone Tottola, which was based on a play by Francesco Ringhieri, L'Osiride, of 1760. It premiered on 5 March 1818 at the recently reconstructed Teatro San Carlo in Naples, Italy. [Wikipedia]
 Other major works at this concert included Robert Schumann, Symphony No.3 in E flat ‘Rhenish’ and Beethoven’s Piano Concerto in C minor No.3.