Thanks to all for your thoughtful replies. This is helpful in gaining perspective on the many facets of trumpet playing and trumpet equipment. For me, it sounds like I need to simply oil the valves and keep blowing! Occassionally I get an amazing tone with a hint of vibrato. A player I know told me this can happen if I am right on pitch, although I sensed it had more to do with a subtle breath modulation. Fact or fiction? Does a perfectly in tune note have a vibrato sound? Just trying to sort out the fiction from fact. Lot's of "tribal knowledge" passed around the world of music.