Cassandra Wilson/Lionel Loueke, Royal Festival Hall

“I’m sorry I’m late,” said Cassandra Wilson to a half empty Royal Festival Hall, after a sulky rendition of “Don’t Explain”, the opening track from her Billie Holiday tribute album, Coming Forth By Day. It was an hour and fifteen minutes since the singer was due on stage and half an hour since the directors of concert promoter Serious had arrived in her stead – amidst boos and irate whistles – to tell us she was refusing to leave her hotel room.

“You want to know where I was?” said the singer, who seemed a little unsteady on her feet. “Billie Holliday had this wonderful saying: ‘Showbusiness, you have to laugh to keep from throwing up’. Well tonight I couldn’t laugh.”

Wilson’s band (who we were told had gone back to the hotel to persuade her to come out) did an admirable job of keeping the show on the road as the singer wandered on and off stage and bickered with audience members in the front row, scolding them for taking photos. Pianist Jon Cowherd’s playing ranged from soft and supple to brilliantly brutish. Reeds-man Robby Marshall provided sensitive embellishments to Wilson’s vocals (still velvety and rich, if a little half-hearted and not always in tune) and violinist Charlie Burnham accentuated the bleary, blues-rock feel that characterises Wilson's album Coming Forth By Day, with yowling, electric guitar-like solos and liberal use of his effects pedals.

What is clear though is that Wilson should not have performed

But for all the positives – and despite an engaging first half set of tumbling grooves, tricksy time signatures and percussive vocals from Benin-born guitarist Lionel Loueke – this was a sorry sort of evening. Who knows what went on backstage, but the Grammy-winning vocalist was clearly not herself. She made two further, arrestingly blunt references to vomit during the truncated, hour-long set and commented that it had been “a weird tour”.

She has since taken to Facebook, however, to accuse Serious of "malicious and unprofessional conduct", describing their employees as "dismissive, disrespectful and in full breach of contract" before drawing further parallels with Holiday, who was "maligned and exploited too much in her life time". David Jones of Serious has denied all of these claims in articles published by The Evening Standard and Daily Telegraph.

It’s all a bit of a mess. What is clear though is that Wilson should not have performed. At her best, the singer holds a legitimate claim to the title of greatest living female jazz vocalist, but this angsty, erratic set by no means did her justice. It served no one – least of all the music and the bewildered, rightfully disgruntled audience. It would have been better if we had all gone home.

@ThomasNRees