Michael, I’d be delighted to meet up with you - or anyone else off the forum who happens past my neck of the woods.
The answers to your questions about why I lift which fingers I do would be very easy to demonstrate but are rather harder to explain - bear with me and I’ll try
You wrote: I don’t understand what or why you’re doing what you’re doing when you go from oxo xxx to xoo xxx on flute or oxx xox to xoo xox on whistle. Why are you lifting finger or fingers on your left hand?
To get a B or something very close as the lower, 4th step of the roll.
You wrote: I get a nice sound with:
whistle:
oxx xox
oxx xxx
oxx xox
xxx xox
oxx xox
The 4th step of that gives a very low tone (flat F#) as the lower passing note (tap equivalent) of the roll - it works, but sounds pretty odd to my ear - not saying it’s “wrong” mind. My fingerings give a slightly flat B as the lower element - sounding much more comparable to rolls elsewhere in the scale - it’s a normal roll pattern of pitch changes - what I play is cdcbc in effect.
Before anyone jumps in, I’m well aware of and have expounded myself upon the theory that the cuts and taps in ITM, including as constituents of rolls and crans, are not in-scale accurate, pitch specific “notes”, but breaks in the sound of the main note. I have also observed elsewhere (as have others), however, that sometimes the pitch of such cuts and taps has a noticeable effect within the mode of a tune, so that even if they are not in-tune notes of the scale, some effects are more or less agreeable. Certainly big pitch jumps in cuts or taps away from the main note are noticeably different from small, closely neighbouring ones.
You wrote: On flute, I play c natural like oxx ooo, but if I played it like you do, I would probably play a c natural roll like this:
oxo xxx
xxo xxx
oxo xxx
oxx xxx
oxo xxx
Similarly to your last example, that produces a pattern that sounds cAcdc - works, but inverts the normal roll pattern of home-up-home-down-home in pitch steps - doesn’t sound like a roll.
You wrote: I figure since a cut on c natural:
oxo xxx
ooo xxx
oxo xxx
doesn’t really “cut it” (ha ha), I “cut” with a tap:
oxo xxx
xxo xxx
oxo xxx
So, my c-nat roll in your fingering of c-nat would be
oxo xxx
xxo xxx
oxo xxx
oxx xxx
oxo xxx
You are right that lifting L2 in the first example immediately above makes virtually no difference to the sound (about a 1/4 tone from C nat to a very flat C#)
You are also right that a cut in the sense of lifting a finger cannot here provide a higher tone. However, your proposal of tapping L1 actually gives a significantly lower tone - a flat A. If you tap L3 as I do in the “cut” (2nd) step (just as you tap R2 in the whistle equivalent I gave based on c nat = oxx xox), you actually get a d above the c nat! (Further, it is the normal and familiar change from cross fingered c nat to d - no “funny stuff” going on with the fingers.) You then suggest to tap L3 in the 4th step, getting a higher note (d) there where you want a lower one. My fingering (xoo ooo or, easier/lazier, xoo xxx) gets you that lower note, a B.
Incidentally, if you use oxx ooo for c nat (sharp and weak on most flutes and whistles), the c nat roll would be:
oxx ooo
oxx xxx
oxx ooo
xoo ooo
oxx ooo
which works just fine (I use it on my piccolo, which does have oxx ooo as its optimal c nat cross fingering) - and you can leave R3 on right through if you like.
I worked out what I do many years ago when playing with a fiddler and trying to play in close parallel to him. I had to work on them quite hard to begin with, but they didn’t take that long to crack and now they’re just part of what I do. They are no harder than other initially awkward finger changes.
Try them in slow motion and compare the sounds produced with your versions.
I’m not especially proselytising them here, just answering the original question about how they may be done if wanted, and I quite accept that many folk don’t want. But they are perfectly feasible and effective if wanted and worked for.
I’ll try to sort out some video demo clips if I can, but probably won’t have time over the weekend.