The truth about tonguing is that it is absolutely *impossible* to play the tin whistle without tonguing. My evidence goes as follow: how do you start a tune without tonguing the first note? How do you begin the next phrase after taking a breath or a pause without tonguing? Well, you can't. The tin whistle is not like the pipes where you squish the air thru to get things going and then sustain the air forever until said squishing stops. No, you absolutely must tongue in order to play the tin whistle.
Having established this point, let me go on to argue that there is a widespread misunderstanding about how one ought to tongue when playing the tin whistle. This point is setting aside the stylistic issues of how much and what kind, which is to some extent is subject to taste. The misunderstanding has its origins in the fact that there are actually two kinds of tonguing: one kind that interrupts the flow of air, and one that does not (or is incredibly minimal). The former kind of tonguing can be understood by reflecting on the way air gets interrupted when you say “tah tah tah tah” etc. The latter kind of tonguing can be understood by reflecting on the way the airflow operates when you say “dah dah dah dah” etc with the tongue touching the roof of the mouth. In classical music for woodwinds, the former is staccato tonguing while the latter is more legato. Let’s call them “tah” tonguing versus “dah” tonguing, respectively.
The “dah” form of tonguing is a very delicate and subtle form of tonguing that often goes unnoticed. In fact, I would venture to say that many whistle players who we might say don’t tongue actually do tongue; it is just in the “dah” form. I’d say Mary Bergin fits in this category. She wings thru tunes so gracefully and beautifully that we don’t notice how she is subtlety sculpting the tune with tonguing all along the way. Rarely do you hear a “tah” or “tut” out of her unless it is a deliberate accentuation as such. Conversely, there are players like Larry Nugent who we accord with tonguing a lot, but what we are really referring to the ornamentation which uses triplets and double tonguing (or the “chitter” as somebody else pointed out) where the staccato nature of the tonguing stands out. However, if you listen carefully, the “dah” form of tonguing is the bread and butter form of tonguing that Larry uses and often in conjunction with slurring. Perhaps the only tin whistle player I can think of who really uses the “tah” form of tonguing as a staple is Micho Russell. But there might be others.
My overall argument is that in comparison to the “dah” form of tonguing, the “tah” form is inferior. All whistle players ought to practice and learn the “dah” form of tonguing thereby learning how to maintain the steady stream of air in a tune. And at least be able to begin tunes as gracefully and unobtrusively as possible and be able to tongue within the parameters of phrases without always having to interrupt the air flow.
We’re not pipers after all. And don’t we thank god for that!!
Anyhow, my point was that tongueing or not is being discussed here until the cows come home. I suppose you can go a long way not thinking about these things, listening to other players and then listening to yourself, weighing things up but arguably I never learned to play the whislte or thought about it much until plunging into the discussions here. But that was not in any way the point.