So, when people play in Eb are we talking about actually shifting the tune over and starting from the D on the Eb flute, or just transposing the tune up into Eb?
Just wanted to know since I’m thinking about asking Terry or Jon C to cook me up a FHP/ GLP style Eb.
Thanks
I’m pretty sure no one is ever going to be talking about playing in Eb on a simple-system D flute.
I would be. I could say that it’s because I don’t want to be a showoff, but really I’m just lazy. 
Playing in Eb on a simple system D flute is murder…infact i once heard Garry Shannon saying that he would rather eat his flute then play in Eb on a D flute.
However i did hear Niall Keegan play once at Scoil Egise.He was playing a D flute.He played through the tune once in D, and then on the fly just moved up to Eb! Genius!
Now that they have played with your brain enough.. You just transpose it to Eb. A lotof the old English flutes played in Eb fairly well when the tuning slide was all the way in. Of course the slide was pulled way out to play in 440. It is strange, as the flute was designed t oplay in the 430-435 range? 
Go figure…
Well, Niall Keegan is a god. 
on the old system flute (8 key), tunes in Eb were described by many as the 'most beautiful of its keys" by people such as Rockstro.
They did it then, so no reason we can’t today.
Keegan and Chris Norman are among those who do it with ease.
It’s only difficult if you’ve not practiced the appropriate exercises that make it easier!
dm
Let me a try a different way of answering. Flutes of different lengths play different scales. On a keyless flute, the name of the flute is the same as the note you get when you have all holes covered. On a D flute, D is the lowest note. On an E flat flute, E flat is the lowest note. So if you know a tune and play it on a D flute, and then play the same tune with the same fingering on an E flat flute, it will come out a semitone higher. You don’t do anything-the flute does it for you.
I have a friend with a transposing harpsichord. She moves a lever, and the whole keyboard, and the doodad that plucks the string moves over one string to the left, so she can play what sounds to the ear like the same tune a semitone apart, but with the same fingering. It’s the instrument doing the transposing, not the player.
What most folks replying were talking about was playing in a key on the D flute that’s a long way from it’s home key of D. (D to G to C to F to B flat to E flat). In this example, only the notes D and G are shared by a D major and E flat major scale. All the others are different. Each step decreases the number of notes shared by each scale. The consequence is that nearly every note of the tune has to be played cross-fingered, or half holed, or with keys, and that makes it challenging. Can be done of course, but it’s challenging.
Hugh
Try the Bach Eb sonata on an 8-key.
I am a somewhat fluent sax player - all keys and modes are accessible- but I am not a fluent simple-system fluter yet: anything more than 2 flats or 3 sharps and I’m reaching for the tylenol.
Oddly, eastern tunes with Bb, Eb, and C# fall nicely on the 8-key.
Back to practice…
As Nanahedran said, a hundred and so years ago when the wooden flute with 8 keys was the only flute for classical music. It was often said that the best sounding keys were Bb and Eb. My R&R. a copy of Chris Norman’s boxwood (by Johnny Gallagher) that I have been playing for about 2 years; definately sounds better (to me) and is easier to play in Eb. I have gotten so I can play be ear in that key. So my question to you is, Why not have keys put on a D to make it chromatic instead of spending money on a seperate flute, unless your D is not to your likeing?
Nelson
The first two paragraphs of what flutefry said but not the last paragraph which is epilix, IMO.
None of the other responses here seemed relevant to me but, then, the way you asked the question attracted same. So perhaps their apparent non relevance is segue.
Well, I didn’t say it in this thread, but no matter. Maybe you overheard me talking with a curious onlooker yesterday?
I will have to learn to play in Eb, and other keys. It can’t hurt. I do some Dm and Gmix and Cmaj. Mind you, I’m just an ITM player, so there isn’t a lot of incentive to play in, say, Fnat (major, minor, or mixolydian). I keep learning those pesky new tunes and forget the other thing.
I have an Eb corps de réchange that I use mainly for solo playing, particularly for dancers in hardshoe. There’s a practical reason for this. Comparing Eb and D bodies for the same flute, the bore-to-length ratio changes, and so with a shorter body, the Eb bore is relatively wider, to oversimplify. There’s a difference in tone quality from the D body. Although still reedy, it’s brighter, has more “presence”, and more sense of projection, too. And the response is crazy. Louder? Hard to say. Maybe. “Concentrated” might be the best word for it. In any case, it cuts through the battering better than the D body does. Eb played on a D body would be Eb played on a D body: nice and dark and woody, but lacking the laser-like intensity I’ve come to want for dancers, especially if I’m unplugged.
Mind you, I love the D body, too. Plus it keeps me socially acceptable.