Shearer, known for his role in the mockumentary This is Spinal Tap and a key voice for characters in The Simpsons, is a political satirist, a funnyman and not a great singer; Owen is a soulful singer who plays piano artfully, has a lovely vocal range and sings meaningful jazz ballads.

They are opposites and the infernal rackets inside each of their heads that give rise to their songs and performance styles are different.

An entertaining film clip demonstrates the range of musical and theatrical experiences that Shearer and Owen have participated in, promising a comical, slightly zany evening. The performance then begins with the three superb musicians – Leland Sklar on bass guitar, Pedro Segundo on percussion and CJ Vanston on piano – taking their places and beginning to play, which they do brilliantly.

There follows two performances in one. Owen sings, quite beautifully, songs that seem to be about mostly negative human experiences: most notably “The Rain is Gonna Fall” and “Mystery”. Alternating with her is Shearer who, being an excellent mimic and comic, gives impressions in song of aspects of Donald Trump (“I Can’t Believe I’m Me”), Rupert Murdoch (“Refined Sugar”) and George W Bush (“Addicted to Oil”): the lyrics are not always hysterically funny, scathing or profound, but mostly hit their mark.

Shearer was on song when he sang, in almost Beach Boys style, “Waterboardin’ USA”, and the most effective song of the night, “Deaf Boys”, which followed an excellent introduction about a priest in Wisconsin who had abused more than 200 deaf boys.

This Infernal Racket has some beautiful blues songs, some quite hard-hitting political satire and a sensational backing band, but I am not convinced a presentation of opposing forces is a formula for the best performance.

Harry Shearer and Judith Owen present This Infernal Racket again tonight (Friday) at the Dunstan Playhouse as part of the Adelaide Cabaret Festival.