Edit: apparently wrong, looking at this shows 2T being one of the narrow blocks: http://www.seatwave.com/lang-lang-tickets/royal-albert-hall-tickets/21-March-2012/perf/385245
Got tickets for this earlier. Had to phone up as the internet was saying there wasnt any left but thought I would chance my luck. Turns out there was only single seats left although the woman I spoke to found 1 set of two seats together and I got them. The other half isnt exactly thrilled but shes happy to get a weekend away in london.