Magnificent player Bill. Hi Paul its John from UK 🇬🇧 the toothless one 😉 om now adding my lip trill to my playing in every way that is possible, such a lovely sound having them there immediately like a lip trill lead into further notes , or from notes leading into a lip trill and so forth. Never in a million years did I think 3 years ago that I would be capable of playing in such a way but hey here i am 3 yrs later playing them . God they take some practice though. , they are very clever little things and i love being able to play them . My opinion if it means anything they are one of the advanced technique that take time to have them 10/10 there when i want them.