Friends,
This topic i remember is already available.Then it can be merged with the earlier one.Generally at the start of a concert with few exceptions will have 25 to 50 people in the audience.Gradually it scales up and the peak strength would be about 200.In case the concert start is at 06:30,the peak attendance would be from 07:00 - 08:30.Once again the strength dramatically starts falling and if there is a speech then once again the strength will be in the range of 50 -75.As i already mentioned there are exceptions to this statistics.
It is very rare to have strength of 200 till the end of the concert.This is true of concerts held in closed halls.The strength would be little more at Fort HS Ramanavami where the capacity is 5000 and this gets filled only for highly popular ones - KY Yesudoss and about 2000 in respect of Sanjay,Ranjani-Gayatri etc.