What can I say about a performance I did not attend? Well, firstly I find it interesting that you chose not to document it in any way other than through the a written account of the audience. From the performer to spectator to the non-live audience, there are inevitably details which will be forgotten, misinterpreted, and distorted as various individuals give their unique account of the live event. I feel this is really fertile ground and opens up a lot of questions regarding the mythologisation of live art.
How much detail do we reveal about a performance after it has taken place? Why do we choose particular mediums to document the work and to what extent do they distort the reality of the live event? What role does the audience play in furthering this mythology?
lock In Brighton 
I think my first question is, do you actually get a sense of a performance you didn’t attend through a written account of an actual audience member?
Can the audience member really express what it was they saw and felt through their written word?
Can they, or we rely on that account, as it’s just from their memory?
When we write about experiencing a Live Art / Performance Art event we can write about the moment when something happened or took place in quite a sterilized way as in “The artist took an empty glass, filled it with water and drank the contents”
Which is great and descriptive but can we ever fully describe the moment and how it felt?
Can we get the sense of the presence from written word?