Well I am of course a beginner to all this pipe/whistle stuff which makes it a challenge, but I found the metal pennywhistles to be very difficult for me to get clear notes on, and not so at all on my plastic tabor pipe, which has a nice clear warm tone.
So as an experiment I ordered two plastic/polymer Dixon penny whistles instead to try- in the keys of high D and low A. (there's a substantial size difference between the two keys).
They arrived today and I am finding them much easier to get good notes on than the metal PWs. Not sure why but the plastic ones make clearer notes and warmer tones for me. Perhaps when i get better I can make the metal ones sound better, who knows.
I was delighted to discover that all my diligent tabor pipe practice is helping me here- the learning curve for these new pennywhistles is way less steep than when i first started tabor pipe. I can already play some of my favorite simple tunes, with only a few mistakes here and there.... so fun!!
I'm not one for playing lots of Irish tunes, but I can play my favorite renaissance and medieval tunes on these, and also some early folk/country dances from various European countries. I'm working on some simple French branles, also things like Nonesuch.