Iron and Wine, LSO St Luke's, London

Since the US label Sub Pop happened upon some of Sam Beam's home recordings and brought out The Creek Drank the Cradle two years ago, this singing and songwriting cinematography lecturer has become a small phenomenon.

Beam lives in Miami, but his hushed, bucolic compositions sound a million miles from the city of bright lights, beaches and Gloria Estefan. Preoccupied with God, death and the small pleasures of everyday life, they are elegiac and autumnal, evoking crisp, dewy mornings or late nights out on the porch.

The singer says he chose the name Iron and Wine (it's from a protein supplement) because it juxtaposed an image of enjoyment with a harder edge, but his sound is definitely more "wine" than "iron".

The second album Our Endless Numbered Days, released in March, brought some percussion into the mix, but tonight Beam is accompanied only by Patrick Mc- Kinney on guitar and banjo, with his sister Sara Beam singing harmonies. He performs several songs alone, putting all the focus on his wonderfully warm vocals, and holding the notes at the end of each line for what seems an uncanny length of time given how unfailingly breathy they are. The effect is to lull listeners into a sense of calm contentment. You have every confidence that Beam is a really nice guy.

At times, this makes it frustratingly hard to focus on the darker content of some of his lyrics, which is where, presumably, most of what Beam might call the "iron" part of his work is located. "Bird Stealing Bread", for example, jealously asks an ex who has a new lover, "Do his hands in your hair feel a lot like a thing you believe in/ or a bit like a bird stealing bread out from under your nose?" But the melody chimes more easily with the sweetness of the earlier line, "I've a picture of you on our favourite day." This lyric is typical of the ease with which Beam's compositions exude a sense of life basically enjoyed, with an acceptance brilliantly summed up in the line, "Life strikes a deal with each coming night," on the last song Beam plays in the set, "Each Coming Night".

It is appropriate that he should be playing in a former church. Beam's lyrics aim for a certain timeless, biblical universality, investing simple declarations such as, "It is good in my lady's house" with poetic weight. The melodies, too, are simple and clear. Like Mazzy Star, Beam varies little from his signature style yet finds almost unimaginable variety within its confines. He just seems to have an unending supply of these manifestly lovely tunes.

Tonight's show steps out of the standard pace and volume just enough for it to be interesting without spoiling the mood. Beam lets his voice rip once, suddenly sounding like Michael Stipe at the stunning climax of "Passing Afternoon". And there are a couple of instrumental codas where an impressively solid yet melodic sound emerges from the two acoustic guitars of Beam and McKinney - I suppose you might call it "folking out".