And, JMFan, you`ve just shown to us all in another thread that the Queen sing John`s songs, Imagine, for example. They don`t see any problem here, though it`s the Queen`s concert, they are generous!!! Besides, you yourself wrote that it was very emotional. Paul`s singing John`s songs is very emotional too. Much more than Julian or Sean singing, which is natural, cause they are the sons.
But you are right, not more than 2-3 (I am repeating myself).