Over recent weeks, American minimalists (all of whom hate to be called minimalists) have invaded London, first Steve Reich and then Philip Glass.

Last night it was the turn of John Adams, the subject of the London Symphony Orchestra’s In Focus series. Alone of the three, Adams has shown a willingness to conduct music by other composers but he’s careful about what he takes on. You might not expect him to be drawn to dark Nordic melancholy, but Sibelius’s music touches him deeply, not least because of the way it builds complexity from simple seeds: the essence of minimalism itself.

Restless and full of suggestions that never coalesce into a single mood, Sibelius’s Sixth Symphony is his most elusive. Individual movements, and finally the whole piece, don’t finish but simply stop, denying easy resolution. This is music that the LSO knows inside out but Adams’s reading was somewhat under-characterised, as if it didn’t want to impose itself.

In Britten’s Four Sea Interludes from Peter Grimes, the thin wash of Suffolk light was suffused with the glint and glare of Hollywood, and it worked a treat. It would be fascinating to hear Adams conduct the complete opera but we’ll probably never have the opportunity.

Adams’s own Doctor Atomic Symphony distils the musical gist of his last-but-one opera. In a typically pithy introduction, Adams outlined the opera’s plot, about the invention of the atomic bomb and its guiding light, J Robert Oppenheimer, and then described how its dramatic impulses were transformed into purely instrumental narrative.

At one level, the symphony is an exercise in scene-setting of the kind beloved of, say, Richard Strauss. On the other hand, it delights in a completely un-European approach to rhythm, colour and structure. Here and there were traces of the rhythmic repetition that we think of as minimalist; but there was also a saturated lushness, a willingness to go for broke.

The opera’s centrepiece is an aria that sets a poem by John Donne; here, the trumpet had the solo voice, bluesy, upfront and entirely American: Adams at his heart-on-sleeve best.
Series continues Thursday. Information: www.barbican.org.uk