Hi I think vibrato is a more appropriate term for what is being discussed than tremolo - but anyway, I think it is easy to think of it in terms of vocal vibrato only now with the harp you have to get the vibrato on the draw. I found that getting the tongue out of the way was very important in getting a good throat vibrato - otherwise one can con oneself into believing one has a good vibrato - listening to the greats like SBWII helps a lot. The way it works for me is I try to get a clean airstream all the way from my lips through to the back of my mouth ( where the uvula is ) and then stop this airflow. If this is done sufficiently rapidly you have throat vibrato - getting a steady rhythm for the stop-start takes time and practice. Varying the speed is more difficult I find. I hope this helps , Shankar.
