It's on Tuesday afternoon in the Paxton Suite (Theatre), Captain Billy and Mr Jericho: Original Savoy Opera Curtain-Raisers, presented by Chapel End Savoy Players from Walthamstow.

Savoy Opera means an opera first performed at the Savoy Theatre built by impresario Richard D'Oyly Carte, the last nine of the 13 G&S works (ignoring long-lost Thespis) first seeing the light of day there.

The theatre opened in 1881 with the premiere of Patience and, until 1889 when The Gondoliers first rowed in, only Gilbert and Sullivan works were performed at the Savoy.

After the politely-named post-Gondoliers 'carpet quarrel' between Gilbert and Sullivan seemed to bring the collaboration to a terminal end, D'Oyly Carte turned to other composer/ librettists and English adaptations of works by people like Offenbach – Grand Duchess of Gerolstein, and Messager – Mirette.

They also included Sullivan's post-Gilbert works (except Ivanhoe), the last two G&S pieces, Utopia Ltd and The Grand Duke, and works by Edward German, one with Gilbert (Fallen Fairies) and Merrie England.

It was these subsequent works, 21 of them upto 1910, that gave rise to the term Savoy Operas which was first coined in 1904, although the name is now synonymous with Gilbert and Sullivan.

Apart from the Gilbert and Sullivan works and a handful of others like Merrie England, the Offenbach and, it can be argued, the Sullivan-without-Gilbert works, most never caught on or have slowly faded away. They are not, however, as obscure in the mists of time as the Savoy companion pieces, short works (usually one-acters) which served as curtain-raisers or afterpieces with a full-length work.

They were common in Victorian London when long evenings in the theatre were the norm.

Not every Savoy Opera was presented with one, although most by Gilbert and Sullivan were, including the pre-Savoy ones produced at the Opera Comique.

Identified to date are 24 such works, including Trial by Jury and Cox & Box, which appeared between 1877 and 1908 at the Opera Comique or Savoy Theatre at initial runs or major revivals of Savoy Operas.

Among other composers were George Grossmith with five and the Cellier brothers, Alfred (the eldest) and François, who penned nine between them, including the joint Mrs Jarramie's Genie.

They were conductors at the Savoy and Captain Billy, the first Chapel End Savoy Players' (CESP) curtain-raisers on Tuesday is by François to a libretto by Harry Greenbank, a young writer with an illustrious but short career in front of him.

It served to fill out evenings of productions of two works at the Savoy, the first two as it happens after The Gondoliers, The Nautch Girl (1891) and The Vicar of Bray (1892), both by Edward Solomon.

After a successful career as a pirate, Captain Billy returns to his home village after many years on the same day that a foundling Christopher Jolly consults the parish register to try and find out who he is.

Billy's wife discovers she is not a widow after all and Christopher that the old devil is the uncle who lost him in the Sahara Desert years earlier – and you thought Gilbert's plots were potty!