“Why can’t they just write everyone’s part in concert pitch?” Students at all levels of music education, from elementary school through university grumble about the fact that instruments are pitched various keys. At least at the beginning brass level we typically only have to deal with two instrument transpositions: Bb and F. Otherwise, brass instruments are considered concert pitch instruments. But even with just two transposed keys it’s not quite as simple as it sounds.
Beginners will typically start on a Bb trumpet (sometimes cornet) or F horn if they play so-called “high” brass. These are both considered transposing instruments since the notes players read are different than the actual concert pitches that they sound through their instruments. In contrast, beginning trombones, euphoniums (at least those who read in bass clef), and tubas are all pitched in Bb, but the notes they read sound in concert pitch. Confused yet?
The underlying rationales for transposing instruments lie in the haziness of history. First, they have to do with pre-valve brass instruments. With the exception of the trombone, players were stuck with one length of tubing and its commensurate harmonic series (see Harmonic Series). Want to play in a different key? Add a crook (a fancy name for a length of tubing) to your lead pipe if you’re a horn player. Otherwise, get a different instrument in the correct key. Second, it makes (some) logical sense to call the fundamental pitch of every instrument “C” regardless of the actual sounding pitch. It implies the natural condition of the instrument with nothing added in terms of accidentals. Third, we have a long history of transposing instruments and a lot of music written for them, and it seems just plain easier to keep it that way than to try to change it!
Like it or not, students and teachers need to embrace the reality of transposition. Even something as simple as tuning in the beginning of a rehearsal requires people to interpret the correct note to play. The oboist plays an A? The Bb trumpeter plays a B. The F hornist plays an E. A teacher running a rehearsal using a transposed score needs to transpose the written notation to concert pitch to determine chord structures and accuracy of parts. A non-transposed score requires a conductor to do the reverse in responding to questions. Directors who work primarily with bands and wind ensembles will typically encounter brass parts written for Bb, F, and C instruments. But teachers of students who start to play more advanced chamber and orchestral literature will eventually need to explain and address a wide variety of transposition challenges.