“Everyone’s a little bit racist, sometiiiimes,” the colourful puppets sing, and I wonder if anyone in the theatre has been taken by surprise by the show's tone.

Surely not. This world-famous musical has been lightly subverting the form for over ten years, mostly by taking musical tropes and inserting sex, swearing and puppets. It's a very successful recipe, but the show is so enjoyable not because of its cleverness, but because of its warmth and humour.

The stage looks great and is cleverly used. The dilapidated street façade of down-at-heel New York townhouses is evocative. We can glimpse the glittering skyline of NYC in the background; this neighbourhood is on its margins. The characters are in the margins too. Unemployed, a bit hard up, struggling with their love lives and the bills.

The themes are universal. There's the puppets in love, the puppets with ennui, the puppets who feel directionless, and a sad, sweet subplot in which two puppets come to terms with their sexuality. The characters are well drawn. The audience roots for these hairy little guys.

The black-clad performers on stage are not only adept actors and singers, but puppeteers too. Many play multiple characters, sometimes having conversations with themselves. That this is almost unnoticeable is testament to the way the puppets are brought to vivid life in their hands. The ‘human’ characters are also brilliantly played and, like in the Muppets, their existence alongside puppets never seems strange.

If you don't know the story, you'll probably know some of the songs, many of which are delivered here in barnstorming fashion. By turns bawdy, explicit and philosophical, the lyrics are matched by music played live by a band beneath the stage. Bringing the action above them even more to life, the musicians are puppeteers too, in their own way.

It's not surprising that writer Robert Lopez went on to join up with South Park creators Matt Stone and Trey Parker to write the similarly risqué Book of Mormon in 2005. Their senses of humour match up exactly. More recently, Lopez was responsible for the songs in Disney’s Frozen.

This musical was written at the turn of the millenium and, in a way, it shows its age. Its broad humour and prude-baiting jokes might not quite hit home with the increasingly sensitive online mob if it was released now – despite its ultimate liberalism and gentleness. But its provenance gives it a free pass. My theatre companion had, by chance, already seen it, not only at the West End but also on Broadway. They loved it all over again.

Avenue Q is running until Saturday at the Grand Opera House in York. Box Office: 0844 871 3024