Jose Luis,
on another forum I and Jen Cluff posted a few recordings of the plugs issue. Her finding is that pacing full-depth plugs into the holes is inconsequential. It was 1 cent=100th of a semitone. I'm not sure how she measured it frankly. In my test with Electrical tape over the holes the only guess came from a pro performer and instrument maker who guess whether or not I had covered the wholes. He was wrong.
I would say that the only difference in tone or sound is not audible. Open holes is a sales gimmick unless one intends to do certain avant garde effects such as quarter tone tuning (Which can be lipped), glissandi, or multiphonics.

Using a ring on any of the the right hand fingers to spread the fingers apart would interfere with finger movement up and down. This is especially true because all movement should come from the joints nearest the palm of that hand below the area of any rings. The only finger that can be said to compromise this motion is the Left index.

Part of the purpose of the practice of long tones is to mind covering the holes. This issue of covering is accomplished with 100% diligence to correcting the problem daily and is an ongoing process. Going fast with the fingers would usually undermine this diligence because it is distracting and one tends to compromise their mental focus. Mind you Jose Luis, I don't know how you've done in this area so I am really not targeting you in any such criticism. The question can be resolved in the fact as to whether or not you can cover the holes when you have the flute down and you aren't playing but just looking at your fingers & how they cover the key holes. The very issue of the difference between the F, E and D keys being of varied location that I mentioned is one that my 80 year -old teacher has complained of. We compared our two flutes of the same brand(Mine from 1982 and his from 1947) and they are different enough to be a real issue. In regard to this issue of covering/sealing the holes with the fingers, Micron said (very correctly) a long time ago that many people have a problem with dry hands and leaks from even the smaller parts of the fingerprints. I think that this issue is more prevalent than most flutists realize. It shows up as a good partial reason that they aren't aware of as to why they buy the high E linkage flutes and also why their tone on certain notes such as D2, Eb2, E2 sounds less than desirable. Some people also have issues with small finger pads and others have issue with finger location on the holes.

It is not my place to teach anyone online but practicing for co-ordination development in the pinkey and 3rd fingers is another issue completely of course. That issue can and should be done by practicing all scales and arpeggios down to the lowest notes slurred, minding one's issues and working them carefully as fast as they can be done musically correct. As one example the f#d7 arpeggio can be tricky because of the C1-Eb1 slur but there are many others like
playing the triplet ||:D2-E2-F#2:|| for about 15 minutes per day. I'm not completely against them, but not all that partial to Wye's books because I have bought and paid for ALL of the books that he used to cherry pick his exercises out of.

Bilbo, you are right...

Also, you are right on about Trevor Wye's shorten version from every exercises. But time is so short to practise ALL the exercises on the market. I guess that's why many teachers all over the world love Trevor Wye's exercises 1-5 & 6. Becoz time is little for us students. I practise at least 4 hours a day and still can't even finish all the scales and exercises. But after 2 years, I have done basic scales and Trevor Wye book 1-6(except circular breathing), now I am on Moyse's daily scale exercises(suggested by sir Galway) - that is a killer, so hard after E.

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my point is, first finish Trevor Wye's basics, then move on to those detailed original exercises -for example Marcel Moyse's exercises.

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Jose Luis, oh so sorry, I didn't know you are so old, I thought you were 30-40 or something ;)

Yes, so much to do, to learn and to play. And so little time available.

My coming back to open holes is completely out of question. Even if they had a bigger impact than told by Bilbo. They are sometimes necessary for modern or special music such as Flamenco. My teacher has just issued a CD on this genre and she uses note bending and the like. Maybe this can be lipped, but open holes surely makes it easier. But I am not going to play that sort of music, I do not like it.

I have always been sceptical about the use of open hole flutes for the vast majority of players. Most of these flutes I see through my workshop have at least one hole plugged. On another forum an experienced flute player/technician has commented that he has discovered that there is noticable leakage on open hole flutes with the light finger pressure that players use.

As an aside a move back to Boehm's original design with open G# would make the flute more reliable with one less tone hole, no double G key & no need for split E mechanism.

Ian

Bassoon & bari sax player.
Woodwind repairer.

Yes, one reason I'm unpluging all the holes now, becoz I found my flute hand position is much better now on open hole flute. It forces me to, lol...^_^

Few years ago, William Bennett came here to give us masterclass, he let me play on his open G# flute, I remember it was Louis Lot, I couldn't play it, not used to it later I heard his flute got stolen.