Mechanical and Physical Considerations
Woodwind instruments each have one major scale whose execution involves lifting the fingers more or less sequentially from the bottom to top. This scale is usually the one notated as a C scale (from C to C, with no sharps or flats) for that instrument. The note written as C sounds as the note of the instrument's transposition — on an E♭ alto saxophone, that note sounds as a concert E♭, on an A clarinet, that note sounds as a concert A. The bassoon is an exception; it is not a transposing instrument, yet its "home" scale is F. For tin whistles the "home" scale is notated as D major rather than C major — the most common whistle, pitched in D, is therefore not a transposing instrument.
Brass instruments, when played with no valves engaged (or, for trombones, with the slide all the way in), play a series of notes that form the overtone series based on some fundamental pitch, e.g., the B♭ trumpet, when played with no valves engaged, can play the overtones based on B♭. Usually, that pitch is the note that indicates the transposition of that brass instrument. Trombones are an exception — they read at concert pitch, although tenor and bass trombones are pitched in B♭, alto trombone in E♭. Music for baritone or euphonium is sometimes written in treble clef, transposed to B♭, but sometimes in bass clef at concert pitch.
In general, for these instruments there is some reason to consider a certain pitch the "home" note of an instrument, and that pitch is usually written as C for that instrument. The concert pitch of that note is what determines how we refer to the transposition of that instrument.
Read more about this topic: Transposing Instrument
Famous quotes containing the words mechanical and/or physical:
“No sociologist ... should think himself too good, even in his old age, to make tens of thousands of quite trivial computations in his head and perhaps for months at a time. One cannot with impunity try to transfer this task entirely to mechanical assistants if one wishes to figure something, even though the final result is often small indeed.”
—Max Weber (1864–1920)
“Genius is no more than childhood recaptured at will, childhood equipped now with man’s physical means to express itself, and with the analytical mind that enables it to bring order into the sum of experience, involuntarily amassed.”
—Charles Baudelaire (1821–1867)