Belfast's Thom Southern and his sister Lucy harmonise so tightly that if you closed your eyes, you'd swear it was one person singing. Upstairs at Whelan's is not a great venue - it's small, oddly shaped and the acoustics are horrible - but it's still a great place to hear up-and-coming acts such as Chocolate Orange and singer-songwriter Rose O'Reilly.

But the highlight of the evening was Thom Southern's band. They were the only group to be granted an encore, and attracted the largest audience I've seen so far at Upstairs.

The following night they played Crawdaddy, which was a better venue for them all round: bigger, with better acoustics and Thom's guitar was amped. His singing voice is sonorous, but it can be vulnerable and dreamy.

Lucy's voice is softer than Thom's - she was nervous about joining the band at the beginning - but despite her hesitancy she soars during songs like 'Waiting Line'.

The band are going to record some tracks for a future EP at Berkeley Street Studios in Santa Monica next month. We look forward to it.