The Olympia, Dublin

Sam Beam's career arc has an appropriately graceful, gradual trajectory to it – a solo singer-songwriter who, as Iron and Wine, crafted achingly beautiful folk songs that attracted an ever-growing fanbase, before expanding his sound to incorporate a full band, replete with dense guitar solos and intricate vocal harmonies. The fanbase kept growing, until his latest album, Kiss Each Other Clean, debuted at an impressive No 2 on the US charts.

His new album marks another evolution in his style, with a more 1970s, languorous lounge vibe, with heavy use of keyboard and horn section. It's a somewhat unexpected route – the influence of Jethro Tull and Fleetwood Mac wasn't obvious on his sparsely arranged early material.

But it's an approach he has embraced wholeheartedly for his live shows. Beam has been responsible for a few of the most memorable gigs in Dublin over the past few years, thrilling crowds at the Olympia and Ambassador, but nowadays Beam and his seven-piece band are producing a kind of fusion funk-folk, which is only occasionally as exciting as that sounds.

His demeanour is that of a dignified Southern gentleman, and with his bushy beard, bouffant hair and dapper jacket, he has a refined, singular stage presence. The musicianship is uniformly excellent, but the imposition of this new style on his folky back catalogue is an experiment that brings mixed results. Every artist should be praised for reimagining their material, but the introduction of jazzy keyboard, flute, oboe and sax on classics such as Lion's Maneand Free Until They Cut Me Down, for instance, sounds like experimentation for the sake of it.

Lounge music is not a genre noted for its ability to convey sincerity, and the earthy, fragile honesty of Beam's songs gets overshadowed in these arrangements – frequently, it felt as if Beam was interpreting his own material rather than just playing it.

It was difficult to gauge how receptive the crowd was to the sometimes radically refashioned songs – many seemed restless rather than absorbed – but it was significant that a closing, and unvarnished, Naked As We Camedrew the most rousing reaction of the night. Beam will continue to enthral and reward, but in time this phase might be considered an interesting, if not entirely successful, digression.