While there’s no reason that a children’s opera should be simple or easy, there’s no real need for it to be difficult either. So I was a little confused going into the Barbican’s performance of Oliver Knussen’s brilliant brace of Maurice Sendak adaptations this Saturday, which was surrounded, despite the works’ subject matter, with a slightly unbecoming aura of seriousness. With a programme note which asked us to imagine a world without Oliver Knussen, and a pre-performance talk which included a joke about Mussorgsky’s Boris Godunov, I did wonder if due attention had really been paid to appealing to the 4–6s. Thankfully, however, a spectacular account of these two short operas from both director Netia Jones and the musicians ensured that these remarkable pieces spoke for themselves.

This hugely impressive new production combined acting from the singers with projected animations closely based on Sendak’s originals, controlled live in performance by Netia Jones herself. The effect was enchanting, with a dynamic feel to the action, and there were plenty of beautiful moments of interaction between the two operas’ leads and the sketches which surrounded them, from a live Max in Where the Wild Things Are kicking a virtual soft toy around, to a live Jennie the dog in Higglety Pigglety Pop! trying to feed a massive virtual baby.

The more famous Where the Wild Things Are (1979–83) began the show. It’s the story of Max, an angry young boy in a wolf costume, who is sent to bed without supper and goes on a distant voyage to the land of the Wild Things. Max is quickly crowned their king, they have a Wild Rumpus, and then he decides to return home, where some soup, still hot, is waiting for him. The original book is low on text, so Sendak provided some more for the libretto.

What brings the book alive is the brilliance of the illustrations, and while Netia Jones’ fidelity to Sendak’s originals was a good thing in most ways, the lack of deviation from them occasionally led to rather static tableaux, including a Wild Rumpus which frankly wasn’t very wild: a single image of the Wild Things swinging from trees makes for an exciting illustration, but not a very dynamic framework for a live performance, despite some subtle jiggling about. The storytelling also wasn’t helped by an imperfect acoustic in which the singers’ voices were often lost, and this may have been the cause of what seemed to be a slight hesitancy to Britten Sinfonia’s account of the score, technically superb though it was, and perfectly directed by Ryan Wigglesworth.

Only minor complaints, though, because the performance was carried by the elegance of the story, by the brilliance of Claire Booth as Max, and most of all by Knussen’s spellbinding music. It may not be uniquely “for the kiddies”, as my fellow Bachtrack reviewer Ted pointed out of an LA performance last month, but there’s nothing impenetrable about the score, complex though it is; perhaps it is even mysterious and alluring in the same way as Sendak’s illustrations.

For me, though, the more impressive work is Higglety Pigglety Pop! (1984–5, revised 1999), which here starred Lucy Schaufer in an impressive and presumaby rather warm dog outfit, as Jennie the Sealyham Terrier who abandons her perfect, comfortable existence in search of adventure, declaring to a soprano plant pot that “There must be more to life than having everything”. While the key influence on Wild Things is clearly Ravel, and particularly his very similar opera L’enfant et les sortilèges, Higglety seems to be all about Lewis Carroll and Alice illustrator John Tenniel: the graphics are strongly reminiscent of Tenniel’s, and the curious cast of animals and a loud baby (think “Speak roughly to your little boy...”) are also slightly familiar. Taking influence from a non-musical source, then, this opera seems to has a yard more musical breathing-space, and it felt a more original creation. In fact, it felt like a step up from Wild Things, in every respect of both the work (the more wide-ranging style of the score; the sharper, neater text; the bigger, more opera-ready story) and the performance (perfect balance in sound; a stunning orchestral performance; a more dynamic, witty set design).

Particularly memorable moments included a curdlingly shrill performance from Susanna Andersson as the Baby who won’t eat, a terrifying, debonair Lion from Graeme Broadbent, and a reappearance from the voice of Claire Booth as Baby’s estranged, well-spoken mother – though Schaufer in the lead role stole the show for a portrayal of Jennie which merited all three of its dimensions.

The final scene of Higglety, in which it turns out the Baby is also a goose, or something, makes very little sense at all. Much like the idea of taking two children’s stories and turning them into complex contemporary operas. It doesn’t matter, though, because however bizarre the project is, its quality is unquestionable.