trans -- transpose selected Humdrum pitch representations


trans -d [+-]n [-c [+-]n] [-k keysig] [inputfile ...] [ > outputfile]


The trans command transposes various Humdrum pitch representations. Transposed outputs maintain proper pitch-interval spellings, except in modal transposition; trans might be used to transpose a work up a perfect fourth, or down an augmented third, or from major mode to Phrygian. A "transposition interpretation" is appended to the output to mark the score as having been transposed. By default, input key signatures are retained in the output, however users can specify any replacement key signature using the -k option.

The trans command is able to process those pitch-related representations listed below. All other inputs are simply echoed in the output. For descriptions of the various input representations refer to Section 2 (Representation Reference) of this reference manual.

**kerncore absolute pitch representation
**pitchAmerican National Standards Institute pitch notation (e.g. "A#4")
**solfgFrench solfège system (fixed `doh')
**TonhGerman pitch system
Input representations processed by trans.

Transpositions are transformations that shift all pitch-signifier values up or down by some amount. Transpositions are specified by defining a diatonic offset and a chromatic offset. The diatonic offset affects only the pitch-letter name used to spell a note. The chromatic offset affects only the number of semitones shifted from the original pitch height.

For typical transpositions, both diatonic and chromatic offsets will need to be specified. For example, in transposing up a minor third (e.g. from C to E-flat), the diatonic offset is `up two pitch-letter names,' and the chromatic offset is `up three semitones.' The appropriate command invocation would be:

trans -d +2 -c +3 input > output

The plus signs above are optional; in their absence, trans assumes an upward transposition. Note that negative offsets can be mixed with positive offsets. For example, trans -d -1 -c +1 will transpose the pitch C to B double-sharp, and F flat to E sharp, etc. (i.e. down one letter name, yet up one semitone).

Modal transpositions are invoked by simply omitting the chromatic offset information. (See EXAMPLES below.)

It is recommended that output files produced using the trans command should be given names with the distinguishing `.tr' extension.


The trans command provides the following options:
-c [+-]ntranspose up(+) or down (-) n semitones
-d [+-]ntranspose up(+) or down (-) n diatonic letter names
-hdisplays a help screen summarizing the command syntax
-k keysigreplace all input key signatures by keysig
Options are specified in the command line.

Note that the -d "option" is manditory rather than optional.

By default, trans maintains any original input key signatures in the transposed output. The -k option allows the user to specify a replacement key signature. Either "pitch-class" (*k[...]) or "pitch-height" (*K[...]) key signatures can be specified. (See the key signature tandem interpretation -- Section 3.)


The following examples illustrate the use of trans.

Transposition up a minor third differs from transposition up an augmented second:

trans -d +2 -c +3 milhaud
trans -d +1 -c +3 milhaud

Enharmonic transpositions can be accomplished by defining the chromatic offset as zero semitones. For example, the following command transposes up a diminished second. It might be used to transpose from the key of C-sharp to the key of D-flat.

trans -d +1 -c 0 moonlight

Transposition up or down an octave requires both a diatonic offset and a corresponding chromatic offset of plus or minus 12 semitones. e.g.

trans -d -7 -c -12 guitar

In addition to exact pitch transpositions, trans can also perform modal transpositions. Modal transpositions arise when the pitch letter names are modified without regard for the precise semitone offset. To invoke a modal transposition, simply omit the chromatic offset specification. The following transposition changes diatonic pitch-letter names (down by two pitch-letters) so that the pitch C will become A, etc.

trans -d -2 major > aeolian

For inputs in major keys, the corresponding outputs will be in Aeolian mode.

For some applications, two or more successive transpositions may be necessary. For example, the following pipeline modifies inputs in major keys so that they are in the tonic Dorian mode.

trans -d +1 major | trans -d -1 -c -2 > dorian

The first trans carries out a modal transposition -- up the interval of a diatonic second. Thus, a work in D major would be placed in E Dorian. The second trans returns the score down the precise interval of a major second. Together, both transpositions would cause an input in F major to be transformed to F Dorian; an input in B-flat major would be transformed to B-flat Dorian, etc.

Whenever trans is invoked, it adds a tandem interpretation to the output indicating that the output representation has been transposed and is no longer at the original pitch. Transposition tandem interpretations are similar in syntax to the trans command itself. For example, the following tandem interpretation indicates that the score has been transposed up a major second.


The tandem interpretation in effect echoes the operation of the original transposition. If a score has undergone more than one transposition, the associated tandem interpretations will be ordered beginning with the most recent transposition. For example, a work that was transposed down a perfect fourth, followed by up a diminished second:

trans -d -3 -c -5
trans -d +1 -c 0

would contain the tandem interpretation:



The following example illustrates the operation of trans. Given the following input:
the command

trans -d 1 -c 2 -k '*k[f#c#]'

would produce the following output:



DOS 2.0 and up, with the MKS Toolkit. OS/2 with the MKS Toolkit. UNIX systems supporting the Korn shell or Bourne shell command interpreters, and revised awk (1985).


humsed (4), **kern (2), kern (4), key signature (3), pitch (4), **pitch (2), recode (4), **solfg (2), solfg (4), **Tonh (2), tonh (4), transposition (3)


It is important not to confused transposed scores with notations of music for transposing instruments (such as the horn in F or the clarinet in B-flat). The **pitch, **kern, **Tonh, and **solfg representations are intended to represent absolute or concert pitch; transposed scores are considered deviations from this convention. The transpose tandem interpretation should not be used to indicate that an encoding is for a transposing instrument. A special tandem interpretation -- beginning *ITr -- is reserved for such designations. The interpretation *Tr means that the encoding no longer represents absolute or concert pitch. By contrast, the interpretation *ITr means that the instrumentalist reads from a score whose pitches are notated differently from concert pitch; nevertheless, the ensuing data is encoded at concert pitch. For example, a trumpet in B-flat plays a B-flat by fingering the pitch C. The absolute pitch (B-flat) is the proper **kern, **pitch, **solfg, or **Tonh encoding. Since the instrumentalist's notation is transposed up 1 diatonic letter-name and 2 chromatic semitones from the absolute or concert pitch, the encoded score will contain the instrument's transposition tandem interpretation


(even though the encoded data is at concert pitch). Note that it is possible subsequently to transpose such a score using the trans command.

Note that by default, key and key signature tandem interpretations are not modified by trans since the **pitch, **kern, **solfg, and **Tonh representations are intended to encode the original key and key signature at absolute pitch.