Are the two types of Contrabass Trombone fundamentally different instruments?

Today, I ask an interesting question:

Are the two types of existing Contrabass Trombone, namely the instruments in F and B-flat, fundamentally different species on trombone?

We universally accept the modern Bass Trombone, pitched in tenor B-flat, as a bass.  No one, except a historical purist will argue this point.  For all intents and purposes, the true F Bass Trombone is extinct.  Because of this, today’s instrument in F, with one or two valves, is universally known as a Contrabass Trombone and not as a Bass.  This leaves the B-flat Contrabass Trombone as the outlier.

F Contrabass Trombone Range

B-flat Contrabass Trombone Range

Is the B-flat Contrabass Trombone, today, a Sub-Contrabass Trombone?

Historically, the B-flat Contrabass Trombone was not made with valves.  This means that the lowest available note was E1.  However, all modern B-flat Contrabass Trombones will have at least one valve, which will make the instrument capable of a low C1.  Both of these limits exclude the pedal range, which again, will extend the range even lower.

Converse to this, the modern F Contrabass instrument is capable of descending to a low F1 without using the pedal range.  Between the two instruments, we have a difference of a 4th in range.  In any other instrument family, we would classify two instruments a fourth apart as separate species.

Trombone players, in general, don’t like the large B-flat instrument.  Common quotes I’ve seen from players are along the lines of, “It’s too big,” It handles like a tank,” “It’s slow and sluggish.”  Oddly, professional tuba players will say the same thing about the B-flat Contrabass Tuba, which is why the C Contrabass Tuba is far more prevalent in professional groups.  The slightly shorter tube evidently makes a world of difference.  To this extent, Miraphone has recently constructed a C Contrabass Trombone with two additional valves.  Players who have played it say that it is a huge improvement from the B-flat instrument.

Players view the two instruments as tools to accomplish the same job.  It is expected that they, as would anyone, use the tool that is more efficient and takes less effort.

But, what if we composers and orchestrators treated the instruments differently?

What if we utilized the instruments as both a Contrabass Trombone (F) and a Sub-Contrabass Trombone (B-flat/C)?

For the standard composer/orchestrator, this would be overkill, but for a Hollywood session composer this could be a welcome addition.  Think of the raspy power of multiple Contra Trombone parts.

Maybe something like this…

I think, that in reality, we really do have two separate instruments that need to be handled differently and separately from one another.  For a creative orchestrator, there is, I’m sure, great possibilities here.