I've just been nudged in the direction of this announcement at the BBC World Service homepage, mentioning that Carbon/Silicon will perform at their "free to speak" 75th Anniversary Concert tomorrow. Word is they'll be playing a short (20 minute) "special guest" slot, prior to headliner Katie Melua. This is very much a last-minute confirmation, just sorted out today (hence the lack of advance warning)

Carbon/Silicon will hit the stage at 8:45pm, and the show is expected to be recorded for future broadcast.