This is the usual articulation in classical flute playing and should need no introduction. If you don't know what tonguing is, try this: blow a long note, and while keeping the note going, quickly flick your tongue against the bony ridge behind your front teeth, as though pronouncing "Ta." Note that you aren't actually stopping the note as much as interrupting it.

Traditional flute players vary in their use of tonguing, but as a rule it's used very sparingly for rhythmic emphasis. Remember much of the stylistic stuff we do on the flute is derived from uilleann piping technique, and you can't tongue on the pipes! That being said, you might hear a flute player tonguing the second and third eighth notes of each beat in a jig:

or doing something like this in a reel:

Obviously, the thing to do is to listen to how other flute players use the technique and draw your own informed conclusions.

The cut is a short, very quick note above the note it ornaments. Try this: play a long F#, quickly lift your left third finger, and put it down again.

What you probably heard was an F#, a flat mushy A, and another F#. Make that middle note faster and shorter, until all you hear is the two F#s. The cut is just a little flap of sound, just like tonguing, that separates the two notes.

Generally you'll want to cut D, E, F#, and G with either the second or third finger of the left hand. Most players I've met use the third finger. The A and the B take a cut with the left index finger. I find that a right index-finger cut can sometimes work better for E and D. (I realize I'm being "handist" here; sorry about that. If you play left-handed, of course you'll need to reverse these directions.) The main thing is to use the same finger consistantly, so you can get to where you don't have to think about the mechanics of the technique anymore.

Cuts are generally used to separate notes of the same pitch; you can also use them to articulate different pitches, especially when going from a lower note to a higher one. It goes like this: play a G, lift both the first and the third fingers, and quickly put the index finger down again for an A.

Try it again, minimizing the time that your index finger is off the hole as much as possible. This is a very important technique, and it's worth investing some effort to get it right. Again, you'll probably need to watch and listen to a good flute player doing it to get the idea.

A tap is essentially the opposite of a cut. Play a long G, and quickly bounce your right index finger off its hole.

As with the cut, what you should hear is two G's with a little flick of sound between them. If you hear G - F# - G, you need to make the middle note shorter. It's important to keep the tapping finger relaxed and to let all the movement come from the joint at the base of the finger. This is the key to the crucial bouncing motion - if you do it right, you shouldn't have to exert any muscular force at all to get the finger back off the flute. I usually lift the finger slightly right before tapping so I can hit the hole good and hard.

The main place I use the tap is in a descending phrase that ends on a long note. Play B - A - F# - G. Now play it again, and shorten that F# until it's the merest tiniest flick of sound and all you're hearing is B - A - G, with a little flapping noise before the G.

It sounds good to give the tap a strong surge of breath and back off when you go up to the G. Not all flute players use the tap this way, but I find it to be a powerful expressive tool. Listen to Conal O'Grada, Chris Norman, and the late Frankie Kennedy to hear some of the possibilities.