What Is Transposing?
Suppose Josh plays the alto saxophone and Trish plays the clarinet. They get together and jam one day. Josh writes a short melody on the sax, notates it, and hands it to Trish to play along with. To their shock and amazement, the resulting sound is terrible. What was supposed to be two instruments playing the same melody in concert ended up as a cacophony! Confused, they set out to understand why alto sax and clarinet can't read the same melody. What they discover is that transposing and the natural keys of instruments has caused this musical calamity. All their lives, Josh and Trish were taught that C is C and D is D and so on. Unfortunately, this is not always true; it depends which instrument you are looking at.
The pitch of any note is a mathematical event. Notes exist as vibrations of air. The speed at which they vibrate can be measured and is expressed in hertz (Hz). The only true measure of a note is its frequency in hertz. A large group of instruments plays in concert pitch, meaning that when they play or read a note on the musical staff, they are getting the mathematically correct answer. When a piano plays a middle C, it's playing a note with a frequency of 261 Hz—it's an exact thing; the piano is playing concert pitch. Here is a list of popular instruments that play concert pitch, also called C instruments:
Violin, viola, cello, bass
Pitched percussion (except glockenspiel)
All the instruments in this list play in concert pitch. There are some exceptions: Guitar and bass transpose an octave down to keep their music in the staff, but they are still considered concert. The piccolo and glockenspiel read an octave lower than they actually play, which also keeps these high-pitched instruments within the range of the staff for reading comfort.
What Does Transposing Mean?
Here is a list of the common instruments that transpose:
Soprano, alto, tenor, and baritone saxophone
Trumpet, baritone horn
There are other transposing instruments, but these are the most common ones.
A great example of a concert pitch is an orchestral tuning note. When a symphony orchestra tunes up, the oboe player plays a concert A note and the rest of the orchestra tunes up to this note. Most metronomes that provide a tuning pitch also provide the same concert A (A = 440 Hz).
A transposing instrument reads the same music as other instruments. The only difference is that when a tenor sax plays a written C, the note that comes out would not register as a C on a tuner or match a C on a piano. An entirely different note comes out! A concert B is heard when a trumpet plays a written C—this is what is meant by transposition. Look at the example in FIGURE 14.1. If you play a short melody for the tenor sax on the top staff, what you actually hear is the bottom staff.
FIGURE 14.1 Transposing Melody
Do you start to see the possibility for confusion? If you didn't know about transposing, you might be very confused. Just think about poor Josh and Trish. Amazingly, transposing isn't always taught in the study of an instrument. Most students just learn to read the notes in front of them. But you are here for more than just playing! You want to understand what you are looking at, and if a score has multiple instruments on it, you can't trust your eyes. You have to know what you're really looking at.
Why Does This Happen?
Good question. Why can't we all just get along—er, play in the same key? There are two possible reasons that certain instruments transpose and others don't. The first is history. Brass instruments rely heavily on the overtone series to make their notes happen. Brass instruments used to add crooks, which were additional pipes, to play in different keys. The French horn was a good example of this. In time, as the instruments evolved and valves were added to the brass instruments, the additional crooks were no longer necessary. Certain instruments evolved into certain keys and stayed there. It's now been so long and there has been so much music written that it would be very painful to change.
Think you're immune to this? Play in a rock band? Imagine this: You play in a blues band and you bring in a sax or trumpet player to expand your sound. When it comes time to teach the melodies, what are you going to tell the musician to play? If she wants to solo on the E blues your guitar player is so fond of, exactly what will you say? You need to know how transposition works.
The second reason is best shown in the saxophone family. There are four saxophones in common use today: soprano, alto, tenor, and baritone. Each of the four saxophones transposes differently. The reason that it's done this way has less to do with history and more to do with the ease of the player. Each of the four saxophones, while physically differing in size, has the exact same system of keys that Adolphe Sax invented in the 1800s. The sax transposes four different ways so that any sax player trained on any one of the instruments could play any of the saxophones without having to relearn anything. Each saxophone reads the same treble clef melody, and the composer makes sure that each part is transposed correctly on paper for the proper sonic result. Some other instruments also do this.