Am 03.04.2009 um 19:20 schrieb Anthony W. Youngman:
Sorry, reading this was painful (I play the trombone, as many of you know :-)
1.64 concert pitch
The pitch at which the piano and other non-transposing instruments play, such music is said to be 'in C'. Officially, it is defined as "A = 440", meaning that the note A in the treble clef indicates a sound that has a frequency of 440Hz. There are other standard frequencies, but they have mostly fallen into disuse.
This convention is used for (almost?) all instruments with multiple sounding parts, eg tuned percussion and strings.
Instruments with a single sounding part (woodwind, brass) follow a different convention and are generally known as transposing instruments, although for some instruments (eg flute, oboe), the two conventions lead to the same result. The trombone is unusual in that music for it can be written using either or both conventions.
1.311 transposing instrument
Instruments whose notated pitch is different from concert pitch. Most of these instruments are identified in their name by their fundamental pitch - this being the note whose wavelength is equal to length of the instrument. For example Concert A is 440Hz, the speed of sound in air is 343m/s, therefore an A clarinet (or any other A wind instrument) will have a length of 343/440 = 78cm. (Or be a power of 2 longer or shorter.)
This note is always written as middle C in the treble clef, and is usually referred to as "being in 'X'" where X is the fundamental of the instrument it's written for. It is normal, however, to leave the "in X" off of the music as being redundant because it's already been specified in the instrument's name. So music marked as "A Clarinet" or "Bb Trumpet" will be assumed to be in A or Bf.
Where an instrument's range falls naturally within the treble clef, the reference to the instrument should always either specify the fundamental as part of the instrument name, or specify the transposition, so the player knows what pitch the music is written in - "alto flute in G", "G flute", "alto flute in C".
If the music is written in C it is normal convention NOT to mention the fundamental, and only say "in C" if it is needed to prevent confusion.
If anybody can improve on those entries I'm all ears, otherwise can somebody update the glossary? For the most part, I've just been far more pedantic, but the existing bit about the trombone is, I'm sorry, just plain wrong!
lilypond-devel mailing list