scaletype manpage

COMMAND

scaletype -- Categorizes **kern data as pentatonic, hexatonic, or heptatonic.

scaletype [-D] [-F] [-p] [input(s)] [> output]

-p		Add pitch-class data to output analysis.
-D		Do not include directory path in the filename when analyzing multiple input files.
-F		Do not include filename when analyzing multiple input files.

The scaletype command identifies the type of scale being used in simple music with no notes outside of the scale. The primary scale categories identified are 5-tone (pentatonic), 6-tone (hexatonic), and 7-tone (heptatonic). Pitch class counts less than 5 notes are labeled as toofew, and more than 7 notes are labeled as chromatic. The program is particularly useful for quickly identifying simple pentatonic melodies in large sets of songs.

Multiple File Input

If more than one input file is given, a list of the filenames will be given with the identified scale type. For example, here are the analyses of the first few songs collected by Helen Creighton in Nova Scotia:

   scaletyle *.krn
       nova001.krn:    hexatonic
       nova002.krn:    hexatonic
       nova003.krn:    heptatonic
       nova004.krn:    heptatonic
       nova005.krn:    pentatonic
       nova006.krn:    hexatonic
       nova007.krn:    heptatonic
       nova008.krn:    pentatonic
       nova009.krn:    pentatonic
       nova010.krn:    heptatonic
       nova011.krn:    heptatonic
       nova012.krn:    hexatonic
       ...

If you want to count the number of songs in a set with a particular scale-type quality, you can pipe the output to the unix commands grep and wc -l:

scaletype *.krn | grep pentatonic | wc -l

For the set of Nova Scotia songs, the resulting count is 66, with hexatonic being 62, and pentatonic being 13.

By default, multiple files will be listed with their full pathnames according to the input. If you do not want to see the directory in which a file is located, you can add the -D option. Also, filenames can be suppressed with the -F option

   scaletype -F *.krn 
       hexatonic
       hexatonic
       heptatonic
       heptatonic
       pentatonic
       hexatonic
       heptatonic
       pentatonic
       pentatonic
       heptatonic
       heptatonic
       ...

The -F option is useful for counting the number of songs in each category:

    scaletype -F *.krn | sort | uniq -c | sort -nr 
      66 heptatonic
      62 hexatonic
      13 pentatonic
       8 chromatic
       3 toofew
 

Pitch-Class Sets

Adding the -p option will add additional pitch-class information after the scale-type designation.

     scaletype -p nova001.krn
         hexatonic	C D E F G A

The scaletype program cannot be used to identify the tonic of the scale, so the first pitch-class note in the list is not necessarily the tonic note.

Input arguments or piped data which are expected to be Humdrum files can also be web addresses. For example, if a program can process files like this:

       program file.krn

It can also read the data over the web:

       program http://www.some-computer.com/some-directory/file.krn

Piped data works in a somewhat similar manner:

       cat file.krn | program

is equivalent to a web file using ths form:

       echo http://www.some-computer.com/some-directory/file.krn | program

Besides the http:// protocol, there is another special resource indicator prefix called humdrum:// which downloads data from the kernscores website. For example, using the URI humdrum://brandenburg/bwv1046a.krn:

      program humdrum://brandenburg/bwv1046a.krn

will download the URL:

http://kern.humdrum.org/cgi-bin/ksdata?file=bwv1046a.krn&l=/brandenburg&format=kern
Which is found in the Musedata Bach Brandenburg Concerto collection.

This online-access of Humdrum data can also interface with the classical Humdrum Toolkit commands by using humcat to download the data from the kernscores website. For example, try the command pipeline:

      humcat humdrum://brandenburg/bwv1046a.krn | census -k

The compiled scaletype program can be downloaded for the following platforms:
• Linux (i386 processors) statically compiled on Jan 12 2005.
• Windows compiled on 2 May 2009.
• Mac OS X/i386 compiled on 10 Sep 2009.
• Mac OS X/PowerPC (version 10.2 and higher) compiled on 13 May 2009.

The source code for the program was last modified on 7 Apr 2009. Click here to go to the full source-code download page.