Blondie, Somerset House, London

The audience for tonight's gig includes many who were not even born when the New York band adopted their Blondie moniker in 1975, but everyone knows all of the words anyway.

In the opulent Somerset House courtyard, Debbie Harry's group perform with the same swagger that propelled them to stardom, reminding or revealing to all how they embedded themselves in our musical psyche.

The initial reception is deafening, but the first few tracks generate little momentum, greeted with respectful applause rather than outright euphoria. This being an outdoor gig in the heart of London, the speakers are turned down frustratingly low, and though we all eventually adjust, there's an odd stasis during the opening numbers as a result.

One person not lacking crowd-rousing charisma is Harry. Sashaying across the stage to an ever-increasing chorus of cheers, she retains an enigmatic, alluring aura that no one appears able to resist. By the time they close with "Heart of Glass", she's worked the crowd into a frenzy, and they erupt loudly enough to flout local noise pollution laws.

Harry's stage presence has not diminished, her voice, the heartbeat of the band's best tracks, shifting from communicative to powerful and back again. Even though she's afforded laudable support by Clem Burke's tireless drumming, and Chris Klein and Tommy Kessler's searing guitar solos, it's the vocals that will linger in everyone's minds longest, whether adding punch to "One Way or Another" or soaring through the standout "Maria".

Indeed, Blondie as a whole possess a rare gift for smoothly switching stylistic gears; the diversity of their back catalogue is often overlooked, but tonight their set encompasses a wealth of genres, all bathed in the band's trademark aloof cool. The lo-fi growls of "Atomic" are balanced with the poppier strains of "Sunday Girl", while proto-rap hit "Rapture" bounces off an irrepressible backbeat.

Equally apparent as they storm through their set is the impressive depth in quality of their music. Everyone sings joyously along to the choruses of "Call Me" and "Hanging on the Telephone", the melodies and lyrics as indelible to the crowd as birthmarks, and each time Harry asks the audience to lend their voices, she's met with a volley of responses.

It's almost 40 years since Blondie first formed and, after tonight, everyone's hoping for 40 more.