Change my mind:

[bloke]

The three trombone J.Rochut etude books (120 transcribed Bordogni soprano voice vocalizes) played down two octaves are more effective low range etudes than those "low etudes for tuba" books.

Bordogni-Rochut are tonal etudes which feature (implied/required) classic tonal music phrasing, and (when played two octaves lower than they appear on the page) actually dip into the extreme low range far more often than the books mentioned in the previous sentence. Playing the Rochut books two octaves lower than written on the page also works the brain a little bit more, whereas transposition at the octave is much easier to cipher than transposition at 15va basso. Finally, playing several of them in a row - both one octave below the written trombone range and then two octaves below - really covers the contrabass tuba range pretty well. If not well enough for all tuba playing, then pull out one's F/E-flat tuba or euphonium and go back through all the ones just played once each again: as written.

[MikeS]

I agree with you completely in terms of developing functional, musical ability in that range. One thing that books like the Snedecor etudes do is give you some practice recognizing the notes in the four-plus ledger line realm. When you encounter them in the real world they are seldom in the staff with an 15va basso on them. Plus, some of the Snedecor etudes are kind of fun to play (but I am probably too easily amused).

[bloke]

I agree with you completely in terms of developing functional, musical ability in that range. One thing that books like the Snedecor etudes do is give you some practice recognizing the notes in the four-plus ledger line realm. When you encounter them in the real world they are seldom in the staff with an 15va basso on them. Plus, some of the Snedecor etudes are kind of fun to play (but I am probably too easily amused).

You covered a point that I meant to cover in my post, but forgot and left it out.

I completely agree with you, and/but I'm not sure this (repeated and continuous epic ledger line reading) is a skill that we need, because most composers and arrangers (when pitches below so-called double low E flat or D are rarely requested) resort to writing them up an octave and notating to play them down an octave. The tendency is even to begin doing that around F, if the tuba line stays in that range for a bit.

Moreover, a whole bunch of ledger lines begin to become a blur, and the person reading the music starts becoming confused as to where the staff actually ends and the ledger lines actually begin. (I have to believe that almost everyone agrees with me on this point, whether a tuba player, a music engraver, or both.)

Truth be told, even though we're encountering more and more of composers and arrangers writing in the really really low range, it's still fairly rare, but the obvious benefit of playing "way down there" is to strengthen our ability to play where we are normally asked to play - which is down to F, E-flat, or perhaps D. The overwhelming obvious trend that has pushed tuba players to extend their range wildly lower is the fact that composers and arrangers use midi sounds to play back their compositions to themselves, which can produce those super low electronic versions of tuba sounds effortlessly. Additionally, many composers and arrangers really don't understand the tuba and are under the impression that the tuba plays an octave lower than the bass trombone (perhaps because they've observed that Tchaikovsky treated the tuba in this manner, yet Tchaikovsky didn't ask for double-low C-sharps, and such).

[Mark]

When I work on Rochut, I usually play the exercise down one octave, then as written and then down two octaves. This makes a great low and high range exercise.

[Matt Good]

Or, play these same etudes in tenor clef, add one sharp and down one octave.

[bloke]

' boosts my self-esteem to plug around in the busy sharp key exercises in books II and III, and then go back and play around in book I.

[Tubeast]

A person I know has taken the trouble to type his favorite Bordogni etudes into Finale and had the software transpose these into all key signatures and resulting tonal ranges.

[bloke]

That sounds like a neat project.

I don't have the software to do that and neither have the skills to use the software to do that. I also don't really have any favorites, though I certainly can ascertain which ones are easier to play and which ones are more challenging.
There are 120 of them in those three trombone books, and I can read them down one octave, I can read them down two octaves, and I can play them where they're written. That's quite a bit - right there - to play on BB-flat, F and B-flat instruments. (I don't find myself playing them down any octaves at all on the euphonium - to tell the truth, but I play them down one and two octaves on the BB flat. As written and down one octave on the F instrument, and as written on the euphonium, so that right there is five ways to play 120 etudes.... I guess 600 "versions")

(I play a lot of gigs in combos with my E flat tuba but don't find myself practicing playing it at home - at least not reading out of etude books - very much, and - as of roughly three years ago or so - I no longer own any C instruments.)