Interesting Thread (aren't they all?).

I remember the first time I played with an old-time group and they asked me what key I sang in. They seemed to have difficulty in understanding my reply to the effect that it depended on the song.

I have also realised that at home, sitting comfortably with a mug of coffee nearby, I can sing in a key that lets me get "way down there".
When I sing in front of an audience, I need to pitch it perhaps a tone higher. It seems that the "stage-fright" which I believe is essential to a good performance, tightens up the vocal chords.

Eddie