Just so everyone is aware, a performance of his Grieg Varations wil take place in a cramped nuclear bunker
Er - no (and "will" has two "l"s).
under a sheet music shop
Er - not exactly.
in the West End of London on the 16th April.
Yes. Even you can get some things correct on occasion, although two in the same sentence (as here) must be an all-time record.
The pianist is
Jørgen Hald Nielsen.
Ivan Erreksion.
Been playing with something other than your banjo, then, have you?
Entrance is free
Er - no.
you will need to pay £10 to get out.
Er - no, but the composer does have a reputation for not refusing cash when it is gracefully offered, so audience members need not feel discouraged from making voluntary donations on the way out if so inclined.
It would be advisable to wear a beard,
Er - why? And upon whose advice? Only yours, presumably - which will doubtless fall on especially stony ground for all the female audience members.
so you have something to stroke
Is this another reference to your non-banjo-playing activity, by chance?
and look interested during the performance.
What or how anyone may look before, during and after the performance (which is of other works as well as mine) is up to each audience member and, again, requires no advice from anyone - not even you.
A celebratory dinner will be held at the Pizza Hut, Oxford Street
Er - no.
where a table for 3 has been booked in advance.
Er - no.
Your post is self-evidently abit short on useful information and almost entirely bereft of factual ditto; I'd have thought that you could do better than that...
Best,
Alistair