I’ve noticed some very good players (mainly Paddy Keenan enthusiasts I think) using back d to grace almost every note on the chanter in the bottom octave
I was taught to use this very sparingly by robbie hannan who won’t even use it to grace c nat, and it would take a lot to undo habits that I’ve picked up over the years
Robbie taught us an alternative to using back d to grace c but whatever it was he was doing i couldn’t assimilate it (sometimes you have to be ready to learn something you’re unaccustomed to)
Has anyone else noticed either trend?
Some pipers don’t like it, but will do other things that other pipes don’t like, such as Back D flutters done with a series of quick swipes of the thumb over the back D hole.
Willie Clancy used the staccato Back D as a grace note to other lower octave notes, and used it quite often, so he liked it. Liam O’Flynn uses it too.
It’s a matter of preference - either one can sound good, or can be totally messed up.
I was once told not to do it, not because I couldn’t, but because the person who told me simply didn’t like it. So I wouldn’t worry about trying to undo it. Just learn to not necessarily do it with each Back D to low note but using it as a variation in the tune instead, and remember…
You can please some of the pipers all the time
and you can please all of the pipers some of the time,
but you can never please all of the pipers all of the time 
I try not to do it every time as it can sound a bit too much. back D is generally a louder note so when used as a grace note it can dwarf the main note I think it depends on your personal preference and your chanter. Ive often got a sharp back D so its forever being taped up (which quietens the note).
Some pipers are against it as it cam be seen as a lazy and bad habit. I like to use it occasionally, if only for the fact that it another technique unique to the pipes. You can’t do this on a whistle or a flute.
It’s one of the things that makes uilleann piping so interesting, the range of styles different pipers use.
Some pipers like to keep their cuts close to the melody note that’s being cut because they prefer a gentle, more subtle effect.
The strongest way you can make a note stand out in the low octave is to cut it with the thumb. Even stronger is if you use the thumb cut while the note is off the leg and you put a silence after the note.
You’ll hear Paddy Moloney do this a lot. Sometimes nearly every beat is accentuated with a thumb cut.
The style of piping that uses a lot of thumb cuts is sometimes called “street piping” because the street buskers gravitated towards the style that would allow them to be heard the best.
I’ll be darned. I’ve been debating on posting the same basic question only my version was more prosaically phrased as “cutting in with the thumb on B & other notes. Yeah or nay?” Never thought of it as gracing with a back D. Much more elegant!
Anyway, I found myself doing this from the day I picked up the pipes (also cutting on the beat as panceltic piper describes); it seemed a good way to shorten/separate notes (especially compared to my understanding of closed fingering at the time) and it also just sounded “pipery-er” to me. Given that much of my listening to that point was Keenan or Moloney, I suppose that might explain that. But it was also really easy (I don’t know why, since it takes a massive effort of will to use that thumb to do something simple like operate the Bb key on my flute, but it is), and just plain felt like the right and natural thing to do.
Then I went to a workshop this spring and got a gentle but thorough spanking (
nope, I’ll provide no further details other than the teacher said it lets the air out of the chanter) and have been trying to switch to what he said to do, which is cutting on B with my index finger and using it or the A finger pretty much exclusively.
I have noticed that on my new chanter that opening the back D even briefly is a little more likely to “spill the wind” from the chanter on the higher notes and can even be a bit risky on B, but … ?
I wonder if I misunderstood Mr. Stern Disciplinarian and he just meant no thumb cuts from B up? Anyway, I’ve noticed other people being “all thumbs” since then, so yeah, thanks, john, for asking this question and thanks to everyone else for answers!
I’ve been told by some people to not do it and by others to do it. Ask ten different pipers and get ten different answers. I like back D cuts and use them prodigiously. Anyway, the main thing is to be able to control whether you use them or not. Beginner/intermediate players sometime get into the habit of playing cuts on whatever note automatically, without thinking about why they’re using them in one place or another. Especially back D cuts. They are very emphatic so they’re handy for a phrase or note you want to emphasise. Use back D cuts as liberally as you want but be sure you can turn them off at will. Understanding how tunes are phrased (listen to lots and lots of Irish music) helps you learn where to place them since you don’t want to use them on the note that should be softened.
About using the upper-hand index finger for cutting, I’ve seen pipers who never use that digit for cutting at all: they use the middle finger to cut A (and sometime G as well) and use the thumb to cut B.
Some only use the thumb cut for C and B while some use thumb cuts for just about any low octave note. Some use the index finger only for B, others use the index finger for B and A, some use it for just about any note. And so it goes.
Like somebody said, watch ten pipers and you’ll see ten different systems of cutting.
One thing I’ve noticed is that I tend to use further cuts for the low octave than the high octave. Thumb cuts and index finger cuts sometimes in the low octave, but in the high octave I usually cut with the adjacent finger: a for G, b for A, c for B, etc.
On most concert pitch chanters I have found that cutting a high octave note with anything other than the note itself or the adjacent note inevitably causes the octave to drop. It’s never occurred to me to cut the high octave notes with the back D. There is probably a reason for that.