The necessity of learning to read proficiently in tenor and alto clefs is a bane to many trombone players at the college and university level. In most countries the sheet music used for initial trombone instruction and performance is written exclusively in bass clef, but in advanced repertoire trombone parts in tenor clef begin to occur with great regularity. Alto clef occurs less frequently but often enough that learning it is necessary, and occasionally other clefs are needed, as well. While developing the reading abilities needed to master music in multiple clefs is an obvious necessity for those trombonists who are pursing performing careers, why trombonists pursuing careers as school band directors need to go to all of this trouble becomes a legitimate question. (A related question is why applied music study is necessary for future band directors at all, but that will have to wait for another time.) Here are two big reasons why clef studies are useful for trombonists in music education programs.
1. Proficiency in multiple clefs greatly increases the amount of music available to you to play. As mentioned above, advanced repertoire for trombone makes frequent use of the tenor clef. One assumes that composers and publishers choose to do this in order to reduce the number of ledger lines needed to notate parts in the upper register, but whatever the reason, the ability to read tenor clef is simply assumed by those creating music for trombonists of a certain level of proficiency. I often say that learning to read tenor clef triples the amount of music available to the trombonist, but even that might be an understatement. In any case, without the ability to read tenor clef a wealth of solo, chamber, orchestral, and increasingly even wind band music becomes inaccessible. Alto clef, while less common, still occurs enough to be a reasonable expectation even when one does not play alto trombone (in fact, the first trombone parts for my orchestra gig next weekend are notated exclusively in that clef despite being intended for tenor trombone). Continuing with the movable C-clefs, learning to read mezzo-soprano clef is not a bad idea, either, as it provides a relatively simple tool for reading Horn in F parts at sight (I will explain how this works below). Learn to do this and you’ll never again sweat when a church music director puts a horn part on your stand and sheepishly asks you to play it. (Yes, this does happen. Fairly often.) Non-transposing parts in treble clef are rare, but those who specialize in high register work should not be surprised to see it. If you play in churches or otherwise with choirs you can expect an occasional need to read tenor voice parts notated in treble clef but with an octave displacement.
2. Proficiency in multiple clefs provides a tool for the band director to be able to read a transposing score as if it were in concert pitch. While the above examples provide ample evidence of the utility of clef reading for the performing trombonist, should that trombonist one day become a band conductor he will find those skills to be a great aid in score reading. In most cases, wind band scores in the United States will have some instruments with parts notated in concert pitch in both treble and bass clefs, some instruments notated in B-flat in treble clef (meaning that the sounding pitch is one whole step lower than the written pitch, sometimes with an additional 1-2 octave displacement), some instruments noted in E-flat in treble clef (meaning that the sounding pitch is a major sixth lower than written, also sometimes with an additional 1-2 octave displacement), and the horns in F in treble clef (sounding pitch a perfect fifth lower than written). Excepting the rare instances in which one encounters a part for D-flat piccolo, clarinet in A, or some other odd transposition, the four possibilities mentioned above provide a comprehensive list of the types of parts one typically encounters in a wind band score. Happily, the bass, tenor, and mezzo-soprano clefs can be used as an easy way to read the transposing parts in B-flat, E-flat, and F as if they were notated in concert pitch.
For parts written in treble clef in B-flat, simply imagine that the part were in tenor clef and add two flats to the key signature (or subtract two sharps). In the example provided below, the D as notated in treble clef sounds a C, which occurs on the same line in tenor clef. Depending on the instrument there will be octave displacements to keep in mind but at least the work of transposition is eliminated.
Incidentally, this way of using tenor clef to read B-flat treble clef parts makes the tenor clef a simple way to train bass clef euphonium players to read treble clef parts which use this transposition, likewise trombone and tuba players who will encounter such parts in British brass band music.
For parts written in treble clef in E-flat, imagine that the part were in bass clef (with octave displacements) and add three flats to the key signature (or subtract three sharps). In this example, the C as notated in treble clef sounds an E-flat, which occurs on the same space in bass clef.
For “French” horn and English horn parts in F, imagine that the part were in mezzo-soprano clef and add one flat to the key signature (or subtract one sharp). No octave displacements will occur in these cases. In this example, the G as notated in treble clef sounds a middle C, which occurs on the same line in mezzo-soprano clef.
This way of “transposing without actually transposing” parts while reading a band score does bring with it a couple of oddities: a few of the written accidentals have to be altered to make this work—for example, written C-sharp in B-flat parts sounds a B natural—and as mentioned before, there are in some cases octave displacements involved. Nevertheless, the obvious utility of being able to look at a full score and know immediately what each instrument’s sounding pitches should be more than makes up for these minor adjustments.
Perhaps instead of trombonists complaining about being required to study multiple clefs in their lessons, players of other instruments should complain that this is not included in their training!