The tuba family encompasses five broadly-similar instruments, consisting of two contrabass tubas, two bass tubas, and the euphonium. As demonstrated in the previous section, all five of these instruments can be traced back to the same creative impetus: the need during the middle nineteenth century for a robust bass brasswind instrument. As a result, the development of the individual members of the tuba family of instruments have followed largely the same path from the 1830s to the present day. The euphonium, although often considered a separate instrument from the tuba, is structurally similar to the tuba in almost every way, apart from its shorter length. It will be discussed along with the tubas in all the following sections.
Before we discuss the individual members of the family, it will be helpful to first summarize some of the common design elements of the tuba family, especially as it pertains to the instruments that one is likely to encounter in modern usage. As with all of the other brass instruments, the members of the tuba family consist of a series of tubes, closed on one end by a mouthpiece and embouchure (the playing apparatus consisting of the lips, tongue, and facial muscles around the mouth), and terminated on the other end with a flared bell. The shape of the tubing for both tuba and euphonium are “conical” in their design, lending a mellower, more diffuse timbre to the instrument than the “cylindrical” trombone and trumpet. In this way, the tuba and euphonium are both related to the horn, which likewise has a roughly conical shape. The baritone is a more cylindrical version of the euphonium, and although not considered in depth within this guide, will be discussed briefly where necessary.
Each member of the tuba family is denoted by its fundamental pitch, or the lowest pitch that can be performed without pressing any valves (playing on what is called the open bugle). Because of historical naming conventions and the use of double letters within Adolphe Sax’s line of saxhorns, the contrabass members of the tuba family are the BBb and CC tubas. In colloquial use, however, these instruments are still called the “B-flat” and “C” tubas, potentially causing confusion for the non-tubist. The BBb tuba open bugle has a length of 18 feet, and the CC tuba is measured at 16 feet. The bass tubas are in the keys of Eb and F, at a length of 13 feet and 12 feet, respectively. The euphonium is pitched in Bb (as opposed to the “BBb” tuba), and measures around 9 feet in length.
Like most of its brasswind cousins, the tuba and euphonium utilize a set of valves to change the harmonic series available to the performer, and subtle embouchure adjustments allow different partials within the harmonic series to be produced. Technically speaking, there are 11 harmonic series’, corresponding to the 11 total pitches starting from the open fundamental (the lowest note playable with no valves pressed) and moving downwards chromatically. In practice, though, most players are only able to play to around the tritone below the fundamental. At that point, the player can only continue down chromatically by switching to a 2nd partial or higher.
The members of the tuba family come with either piston or rotary valves, the selection of which is based on personal preference and/or playing tradition (see Figures 2 and 3).
Fig. 2 – Example of rotary valve. This is a CC contrabass tuba.
Fig. 3 – Example of a piston valve tuba. This is an Eb compensating bass tuba (photo by Michiko Saiki).
The rotary valve consists of a paddle connected to a horizontally-placed rotor, and when depressed, different sections of tubing are opened and closed to change the overall length of the tuba/euphonium (thus changing the harmonic series available to the performer). The piston valve, in comparison, consists of a vertically-oriented piston that opens and closes various sections of tubing when depressed. The musical differences between the two valve systems are largely confined to subjective difference in performance, although subtle differences in tone may be noticeable to the refined ear. In general, rotary valves offer a greater amount of control over legato playing, while pistons offer a greater degree of articulate control. These differences are mostly subjective, though, and unless a specific type of valve is called for in your composition, there is little disparity between the two valve types.
One small quirk of the different valve systems of the tuba family is the fact that many tubas actually combine both kinds of valve in their construction. When a tuba has more than four valves, the additional valves are almost exclusively of the rotary valve variety (see Figure 4).
Fig. 4 – Example of a CC contrabass tuba with four piston valves and one rotary valve (the large circular valve)
Five-and-six-valve tubas either have all rotary valves, or four piston valves and one or two rotary valves. Instruments that follow the second case are still referred to as piston valve tubas, as that is the dominant style among the five or six valves present. The addition of fifth and sixth valves on a tuba is due to the use of a non-compensating valve design; this will be discussed shortly.
While the different keys of tubas are often seen with both rotary and piston valves (and sometimes both at the same time), the euphonium is almost always constructed with piston valves. There are a few seldom-seen rotary valve versions of the euphonium in different parts of the European mainland; the use of these instruments is largely confined to Europe, although they do appear from time to time in North America (especially in use by orchestral tubists who require a tenor tuba for one reason or another and prefer the more stereotypically “tuba-like” construction of these rotary euphoniums). The dominant form of the euphonium is the British-style compensating piston euphonium. This brings us to another quirk that often causes issues for non-tuba-playing composers: the difference between compensating and non-compensating instruments.
Since the addition of multiple valves in combination causes intonation deficiencies in the low range of the tuba and euphonium, two different systems are used to correct the low range intonation of the tuba family instruments: the compensating and non-compensating systems.  In a compensating system, an additional set of tubes for each of the first three pistons is activated when the fourth valve is depressed. In this way, the generally sharp intonation tendencies of the lower notes of the tuba (between the first and second partials) are corrected by depressing the fourth valve and continuing downward in the normal fingering pattern. The non-compensating system, in contrast, deals with the intonation deficiencies of the low range by simply adding one to two more valves of smaller tubing length; this allows for a wider range of fingering options when playing in the low range, thus correcting intonation deficiencies by attrition.
The use of either compensating or non-compensating valve systems is dependent partially on playing traditions, and partly on player preference. Although there was a strong early twentieth century American euphonium-playing tradition that preferred the use of non-compensating baritone-euphonium hybrids, the dominant euphonium tradition across the entirety of the Western world now favors the British-style compensating euphonium, commonly referred to as a 3+1 valve system due to its configuration of three standard pistons and one compensating valve. There are also a small but noticeable number of compensating tubas in common use. Notwithstanding the existence of a few prototype compensating tubas in the keys of F and CC, the compensating system is largely relegated to Eb bass and BBb contrabass instruments. Both tubas are considered hallmarks of the British and American brass band playing traditions, although the Eb 3+1 compensating tuba has slowly gained traction outside of the brass band world over the course of the twentieth and twenty-first centuries. The rest of the bass and contrabass tubas in professional use across the global tuba community are non-compensating, with five or (in the case of some F tubas) six valves. As discussed in the previous section, the boundaries dictating the particular tubas that one chooses to play are often tied to regional preferences.
The choice of which tubas to use can
be summarized as such: in North America, most beginners start on the BBb tuba,
and then eventually switch to using both the CC tuba and a bass tuba (with a large
bias towards the F tuba over the Eb tuba, although the use of the Eb tuba has
become much less stigmatized over the last few decades). In the European
mainland, many tubists prefer the F tuba as their default tuba, although there
are pockets of Eb tuba usage. For a contrabass tuba, the Austro-German
preference is highly biased in favor of the BBb rotary valve tuba, although the
CC tuba does pop up occasionally. Elsewhere on the mainland, the CC tuba is
quite popular. In the British Isles, the Eb 3+1 compensating tuba still reigns
supreme, with the CC contrabass tuba increasingly gaining ground as the
contrabass tuba of choice for professional work. In many other tuba playing
cultures throughout the world, the unofficial “international standard” takes
hold: the CC and F tubas are the horns of choice, although again, this may be
subverted from time to time. This brings up possibly the most important point
of this entire section: when writing specifically for the tuba, never
assume for a certainty which key or style of tuba you’ll be writing for.
The best course of action when writing for the tuba is to either write for the
instrument from a broad standpoint (i.e., for the bass tuba, or the contrabass
tuba, or the euphonium), or to specify the exact instrument you’re writing for
and make that a part of the composition’s framework.