Here was an object lesson in performance and a rich musical feast from a woman most probably still see as a pretty face who sings pleasant dancefloor-filling tunes.
On stage alongside her were the sextet who play on her silver-certified 2014 album, Wanderlust, a collection of Eastern European-flavoured, fairytale-inspired songs written with Ed Harcourt.
That album was performed in its entirety, the singer clad in a short embroidered red frock that hinted at Russian national dress, her two violinists and backing singers in complementary brief pinafores.
The attention to detail in every department suggested a show destined for much bigger venues, but it was Ellis-Bextor's stage-craft and rapport with the audience that sold the material so successfully.
It is a fine album, but the queue to buy a signed copy at the end suggested that many of the crowd did not know it beforehand.
In amongst highlights like single Runaway Daydreamer, ballad Young Blood, and rocker 13 Little Dolls, there was room for one of Harcourt's own songs and one by Ellis-Bextor's first band The Audience, complete with a memory of playing King Tut's as a teenager.
All that was before the same musicians transformed themselves into a disco band, channelling Nile Rodgers and Bernard Edwards with the Chic strings, and the front woman returning to the stage in a sparkling swimsuit and chiffon topcoat to serve up Groovejet, Moloko's Sing It Back, and, of course, Murder on the Dancefloor.
It was a well-trailed change of pace executed with aplomb, and would have been a fine finish except for a final trick when the singer and Harcourt rematerialised at the mixing desk to silence the Oran Mor chatter with an unplugged version of Wanderlust's Interlude.
A classic gig.