I have several instances of singing concerts before my gurus. For now I will just illustrate 2 examples of concerts which Shri KSK attended. The first was a concert at the TTK library inside Shri TT Vasu's house. It must have been 1991/92 am not too sure. I remember singing an RTP in Natakurinji. I don't think I was too nervous or anything but I was definitely keen to impress him. After the concert when I met him the next day he told me "You are not old enough to sing Natakurinji, but despite that you did a good job." I never understood what he meant by that. After all should there be age criteria for singing ragams? The during one of my guru's concerts, I was singing along and I heard him sing Natakurinji and realised a few things about what he said. Finally I heard some of my students sing I knew exactly what he meant!
The second instance was a concert at the Kasturi Srinivasan Hall for the inauguration of the S Kalyanaraman Trust in memory of his 1st death anniversary. I had sung Todi as the main piece. After the concert my guru told me "The beginning stages of the alapana you did well. But later you realised that you are a performer and had to do a few things to please the audience. I don't blame you for this." Again I never got what he meant. Several years later I realised it was probably the "Gentleman" in him chiding the "Player" in me!