To call last night’s Nico Muhly extravaganza at the Barbican a concert of two halves would not go far enough. It was more like two concerts, with a surprisingly short gap between them. The first was made up of three new classical works played by the Britten Sinfonia, and the second was a set of arty folk numbers and other chamber miniatures by Muhly and others. The whole evening was a provocative mixture of styles – if not always a successful one.

The pop/classical question was on the table in the first half as well as the second. Owen Pallett writes loveable and inventive pop music (he is a solo artist, who used to be known as Final Fantasy) and is a talented violin player and arranger for strings. But his Violin Concerto, receiving its world première with soloist Pekka Kuusisto, sounded unfortunately naïve, and neo-folk in a way that's more akin to the days of Vaughan Williams and Bartók than to more current work. Kuusisto gave it an enthusiastic performance, capturing a sense of drama that the rather meandering passagework need not have inspired, but this was a disappointingly unassured compositional effort from a musician so very laudable in other contexts.

Missy Mazzoli’s Violent, Violent Sea, which opened the concert, was a more compositionally alert engagement with pop music, reminding me strongly of the icy string textures on Björk’s Homogenic. But unlike in Björk’s music, there was a lack of melody and a certain stifledness to the sound. This wasn’t a hugely original work, with some predictable orchestration and not that much momentum, but it did contain some neat textural changes, and the overall effect was intriguing.

Better was the world première of Nico Muhly’s Cello Concerto, played expertly by Oliver Coates. The piece was not particularly radical, by any means, being classically proportioned and neatly structured. But it was well composed enough to be enjoyable. The trick to this work – as I suspect with other pieces by Muhly – is the assuredness with which it is written: even when he’s being bland, it’s sort of an interesting bland. He has a way of making his compositional choices sound self-aware and plausible, and this was a refreshing effort. Coates was neat, accurate, and an engaging presence on the stage. André de Ridder conducted, here as elsewhere, with assurance if not sparkle.

In its own terms, the second half was a decent set of performances; there were a couple of enjoyable miniatures by Muhly (including one which was, according to its composer, “Like, the European première or something?”) and some guest turns from violist Nadia Sirota and Owen Pallett himself on violin. More prominently featured were guitarist, banjo player and singer Sam Amidon, and Doveman (Thomas Bartlett), who played keyboards and percussion and sang very quietly.

The band pieces varied widely in how arted-up they were, one suspects in a pattern corresponding to Muhly’s level of involvement, and my favourites were two from the opposite ends of this spectrum. First, a relatively benign banjo-led song about a train, and second, the elaborate closing piece which was very much a through-composed effort, featuring stuttered, repeating lines of text and extended banjo-playing techniques.

The whole of this half was a testament to certain contemporary trends in the coming-together of classical and popular music. This is basically a good thing, in my books; as someone who listens relentlessly to pop music when not in the concert hall, I love to see genres colliding and intermingling, and like to believe that such collision might constitute the future of music. But the bizarre bipartite structure of this concert overall actually ended up emphasising the hugeness and insurmountability of the differences between classical and popular, relying as it did on a complete change of setup, equipment, lighting effects, and musical substance. It also required two entirely different listening approaches from the audience. It’s impossible to enjoy both halves of a concert like this if you’re listening for the same things throughout.

The two halves were so different, and shared so little, as to drive a wedge between the classical and the popular more than it brought them together. Particularly ironic, as all the actual music on display underlined the fact that these two poles are not really that far apart. If classical and popular do feature in each other’s futures – and I sincerely hope they do – the concert format will need to be thought through a little better than this.