Provided by: abcmidi_20070318-3_amd64 
NAME
abcmatch - search sequences of notes in an ABC file
SYNOPSIS
abcmatch data-file [number] [-a] [-br d] [-c] [-con] [-ign] [-length_hist] [-pitch_hist] [-qnt] [-r n]
[-v] [-ver]
DESCRIPTION
abcmatch searches an ABC file containing (potentially) many tunes for specific sequences of notes. For
example, if you know a few bars of a tune, you can use this program to find the tune having this sequence
and perhaps identify the tune.
At a minimum, abcmatch requires two files. A template file called match.abc which contains the bars that
you are searching for and a large file consisting of a hundred or more ABC tunes. The program
automatically loads up the match.abc file and then scans every tune in the large file.
Though the program can be run stand-alone, it is really meant to be run with a GUI such as runabc.tcl
(which is not yet part of Debian). Most of its output is rather cryptic.
THE MATCHING PROCESS
The template file must be a well-formed ABC file containing the basic X:, M:, L:, and K: headers as well
as the bars to be matched. (Normally, this file is created by runabc.tcl.) It is important to finish each
bar in the match file with a vertical line.
abcmatch uses the key signature to figure out the relative position of the notes in the scale, and to
determine all the assumed sharps and flats. Therefore the program can find matching bars in a tune that
has been transposed to another key, as long as the key difference is not too large. Matches are output in
a list format looking like
29 30 4
30 31 4
Each line indicates a particular match found by the program. The first number on each line gives the
relative position of the tune in the data-file, while the next number gives the X: number of that tune.
The last number is the bar number of the matching tune. Bar numbers are counted sequentially from the
start of the tune, and all V: and P: indications are ignored. That is, the bar number returned by
abcmatch may not match bar numbers printed by one of the PostScript-producing ABC processors such as
abcm2ps or abcmidi-yaps.
For the purposes of matching, abcmatch ignores all guitar chords, lyrics, note decorations (e.g.,
staccato markings), grace notes, etc. In chords such as [G2c2], only the highest note is considered. Any
warnings or error messages from the ABC parser are suppressed unless the -c option is given.
OPTIONS
-a Report any matching bars. By default, if the template file contains a sequence of several bars,
the program will try to find places in the data file where the whole sequence matches. With this
option, it returns all places in the data file where any of the bars in the template file match.
-br d `Brief mode' is designed to identify groups of tunes sharing common bars. In this mode, the
program determines the number of all bars in each tune from the data file which are also present
in the template file. If the number of common bars is greater than or equal to the value of the d
parameter, the program reports the tune and the number of common bars. Currently there is no user
control of the matching criterion; the rhythm must match exactly, and the notes are transposed to
suit the key signature.
-c Display error and warning messages from the ABC parser (which are suppressed by default).
-con Do a pitch contour match. In this case, the program uses the key signature only to indicate
accidentals. The pitch contour is computed from the pitch difference (interval) between adjacent
notes. That is, C2 DE, c2 de, and G2 AB all have the same pitch contour.
-ign Ignore simple bars.
-length_hist
This does no matching at all but returns a histogram of the distribution of note lengths in the
data file. The output looks like
length histogram
12 100
24 20
36 6
48 2
72 4
where a quarter note is 24 units, an eight note 12 units, a dotted half note 72 units etc.
-pitch_hist
This does no matching at all but returns a histogram of the distribution of pitches in the data
file. The output looks like
pitch histogram
64 2
66 9
67 11
where the first number on each line is a MIDI note number and the second is a count of the number
of times that note occurred.
-qnt Do a quantized pitch contour match. This works as described above for the -con option, but will
also quantize the intervals as follows: Unison and semitone intervals are assigned value 0, major
2nds to major 3rds value 1, and a perfect 4th or greater value 2. Negative numbers are used for
descending intervals.
-r n Resolution for matching. If the n parameter is zero, a perfect match must be found, meaning that
the lengths of each note in a bar must match exactly in order to be reported. The larger the value
of n, the looser the match will be. Note lengths are converted into temporal units where a quarter
note is normally assigned a value of 24 (therefore an eighth note has a value of 12, a sixteenth a
value of 6, a half note a value of 48 etc.) If you specify a temporal resolution of 12, then the
pitch values of the notes only need to match at the time units that are multiples of an eight
note. This means that the program would match the two bars C2 D2 and C C D D, as well as C2 D2 and
C/D/C/D/D2. By selecting a suitable value for n, you can search for matches only at the beginning
of a measure or at the beginning of each beat.
-v Run verbosely.
-ver Display the program's version number.
LIMITATIONS
The program has some limitations. For example, the data file must contain bar lines, and tied notes
cannot be longer than the equivalent of 8 quarter notes. A resolution (-r option) that is too small may
cause some buffers to be exceeded. When there are differences of key signatures of more than 5 semitones,
the program may transpose the notes in the wrong direction. Also, tunes with more than one key signature
or time signature may not be processed correctly.
SEE ALSO
abc2midi(1), midi2abc(1), mftext(1)
AUTHOR
This manual page was written by Anselm Lingnau <lingnau@debian.org> for the GNU/Linux system.
VERSION
This manual page describes abcmatch version 1.42 as of 21 December 2006.
24 August 2007 ABCMATCH(1)