Queen's University Students' Union welcomes Arborist, Alana Henderson and Sons of Caliber, writes Chris Jones

Tonight sees an unusually low-key line-up for Queen's University Students' Union's regular live music night, and there are problems afoot. Folk duo New Ancestors were slated to play their first Belfast gig after changing their name from The 1930s, but apparently a broken arm has put paid to that, and so Sons Of Caliber have stepped in at short notice.

This, coupled with the fact that the Queen's freshers' ball is going on downstairs in the Mandela Hall, means that for opening act Arborist, there's a strange atmosphere in the room – a couple of hundred apathetic students getting a few drinks in at the bar before heading downstairs, and a small number at the front waiting to hear some live music.

To add to the drama, Arborist have also been forced into a late change. 'The band were supposed to be here, but they deserted me at the last moment,' says Mark McCambridge, with what we hope is a measure of irony. He later confirms that work commitments meant their drummer couldn't make it, and so it’s one man against the masses.

Fortunately, McCambridge is up to the task. With only a couple of low-key releases under his belt, he has already supported acts including Low and British Sea Power, and so he is well used to the task of winning over a sceptical audience.

The opening 'Incalculable Things' is an immediate attention-grabber, its fingerpicked guitar line cyclical and hypnotic. But McCambridge's greatest weapon is his ragged croon, pitched somewhere between Bill Callahan and Richard Hawley, and well capable of piercing the student din.

It helps that McCambridge – who has spoken in interview of his preference for studio work over playing live – approaches his set with a measure of insouciance – 'You get the idea,' he says drily after stopping one song dead where on record it might fade out – and outright defiance.

Songs like 'Hundreds Of Ways' are warm and inviting but with a dark heart, and the performance is intense, edgy and absolutely compelling. 'This has been bizarre,' says Cambridge as he says his goodbyes. It's also been a success.

In contrast to Arborist, Alana Henderson has a friendly crowd to play to. The bar has emptied of freshers, leaving a captive audience of a few dozen, and judging from the whoops that greet her arrival, Henderson has some devoted fans before her. Like Arborist, she too performs solo rather than with her band, but she accompanies herself with cello – plucked, bowed and occasionally bashed – rather than guitar.

Henderson's choice of instrument (and her idiosyncratic way of playing it) is one way in which she asserts her individuality, but it's by no means her only weapon. She has a whooping, Joni Mitchell-ish voice and a propensity for verse melodies that snake across her words, sometimes taking several lines to resolve. Meanwhile her choruses – such as those of 'Wax And Wane', 'Song About A Song' and 'Museum Of Thought' – tend to hit their mark.

It's Henderson's lyrics, however, that are the real star. She's a confessional songwriter, fearless in her efforts to document the bitterness, pain and sorrow associated with the end of a relationship, and inventive with it.

'Wax And Wane' is truly poetic, and worthy of comparison with Neil Hannon in its style and flair, while 'Museum Of Thought' is seriously clever, an examination of the shared history that couples have, and that future partners will never gain access to after the break-up.

Love and loss have given rise to countless songs full of clichés and platitudes, but Alana Henderson reminds us that it doesn't have to be that way. There are still jewels to be mined.

And so to tonight's accidental headliners, Sons Of Caliber. There's still a respectable crowd to see them, though nothing on the scale of recent Radar nights (such as when Not Squares packed the place out three weeks ago). The four-piece barrel in with a rollicking folk-pop song reminiscent of Icelandic band Of Monsters And Men – acoustic guitar, bass, drums, violin and some stirring male-female harmonies.

In fact, they are at their best when they keep the tempo high – in their quiet moments the songs can lack a bit of character and melt into one, while Andrew Farmer's heavily accented (affected, even) vocals make it hard to pick out the words. It's unfortunate, too, that he should dismissively thank 'Alana Henderson and the tree surgeon', when in fact he was comprehensively outsung by Mark from Arborist.

A solid but unspectacular set ends on a high note with another rousing hoe-down full of sawing violin, energetic strumming and battered skins, the drummer's face locked into a grimace of concentration and effort. But we've already heard the best songs – and the best singing – of the night.