Classical music radio station BBC Radio 3 has been posting excerpts from the choir's performances online, and you can listen to them too via the BBC's free iPlayer site.
Links are provided below and for the best listening experience headphones are recommended as the sound quality is remarkably good.
You can also listen to the full performances via the LSM Radio player using the links below. First is the Rachmaninoff Vespers.
And here the Latvian Radio Choir teams up with the BBC Scottish Symphony Orchestra: