To check out this repository please hg clone the following URL, or open the URL using EasyMercurial or your preferred Mercurial client.

Statistics Download as Zip
| Branch: | Revision:

root / onto / tm / doc / template.html @ 0:1e44d666ced1

History | View | Annotate | Download (11.9 KB)

1
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
2
<html 
3
  xmlns="http://www.w3.org/1999/xhtml"
4
  xmlns:mvcb="http://webns.net/mvcb/"
5
  xml:lang="en"
6
> 
7

    
8
  <head>
9
    <title>Temperament Ontology: Temperament Ontology</title>
10
    <meta http-equiv="content-type" content="text/xhtml+xml; charset=utf-8" />
11
    <link rel="mvvb:generatorAgent" type="application/rdf+xml" title="DOAP" href="http://rdfohloh.wikier.org/project/specgen" />
12
    <!--<link rel="stylesheet" type="text/css" href="http://example.org/style.css" />-->
13
        <link rel="stylesheet" type="text/css" href="style.css" />
14
  </head>
15

    
16
  <body>
17

    
18
    <h1 id="title">The Temperament Ontology</h1>
19

    
20
    <!--<h2 id="subtitle">LONG Temperament </h2>-->
21

    
22
    <h3 id="mymw-doctype">Working Draft &mdash; 18 Dec 2009</h3>
23

    
24
    <dl>
25

    
26
      <dt>This version:</dt>
27
      <dd><a href="http://purl.org/ontology/temperament/draft1-20091218/">http://purl.org/ontology/temperament/draft1-20091218/</a></dd>
28

    
29
      <dt>Latest version:</dt>
30
      <dd><a href="http://purl.org/ontology/temperament/">http://purl.org/ontology/temperament/</a></dd>
31

    
32
      <dt>Last Update: 18. Dec. 2009.</dt>
33
      <dd>Date: 18. Dec. 2009.</dd>
34

    
35
      <dt>Editors:</dt>
36
      <dd>Gyorgy Fazekas, Centre for Digital Music Queen Mary University of London</dd>
37

    
38
      <dt>Authors:</dt>
39
      <dd>Gyorgy Fazekas, Dan Tidhar, Centre for Digital Music Queen Mary University of London</dd>
40

    
41
      <dt>Contributors:</dt>
42
      <dd>See <a href="#acknowledgements">acknowledgements</a></dd>
43

    
44
    </dl>
45

    
46
    <p class="copyright">You are granted a license to use, reproduce and create derivative works of this document under <a rel="license" href="http://creativecommons.org/licenses/by/3.0/">Creative Commons</a>.</p>
47

    
48
    <!-- ===================================================================== -->
49

    
50
    <hr />
51

    
52
    <h2 id="abstract">Abstract</h2>
53
    <p>
54
                The temperament ontology can be used to give a detailed description of the tuning of an instrument.
55
                It is developed in the OMRAS2 project, and intended to be used in conjunction
56
                with the <em><a href="http://purl.org/ontology/mo/">Music Ontology</a></em>, 
57
                for example, when describing the tuning that was used in a particular harpsichord recording.
58
    </p>
59

    
60
    <h2 id="status">Status of this Document</h2>
61
    <p>
62
      <strong>This is a work in progress!</strong> This document is changing
63
      on a daily if not hourly basis. Comments are very welcome, please send
64
      them to <a href="mailto:gyorgy.fazekas@elec.qmul.ac.uk">gyorgy.fazekas@elec.qmul.ac.uk</a>. Thank you.
65
    </p>
66

    
67
    <h2 id="contents">Table of Contents</h2>
68
    <ol id="toc">
69
      <li><a href="#intro">Introduction</a>
70
        <ol>
71
          <li><a href="#s11">About instrument tuning</a></li>
72
          <li><a href="#s12">An open-ended temperament description model</a></li>
73
          <li>
74
            <a href="#s13">The many ways of describing temperaments</a>
75
            <ol>
76
              <li><a href="#s131">The Circle of Fifths</a></li>
77
              <li><a href="#s132">Deviation from Equal Temperament</a></li>
78
            </ol>
79
          </li>
80
        </ol>
81
      </li>
82
      <li><a href="#sec-glance">Temperament  ontology at a glance</a></li>
83
      <li>
84
        <a href="#overview">Temperament  ontology overview</a>
85
        <ol>
86
          <li><a href="#s31">Example</a></li>
87
        </ol>
88
      </li>
89
      <li><a href="#reference">Cross-reference for Temperament  classes and properties</a></li>
90
    </ol>
91

    
92
    <h3>Appendixes</h3>
93
    <ol id="appendix">
94
      <li><a href="#references">Normative References</a></li>
95
      <li><a href="#changes">Changes in this version</a> (Non-Normative)</li>
96
      <li><a href="#acknowledgements">Acknowledgements</a> (Non-Normative)</li>
97
    </ol>
98

    
99
    <hr />
100

    
101
    <!-- ===================================================================== -->
102

    
103
    <h2 id="intro">1 Introduction</h2>
104

    
105
    <p>The temperament ontology aims to describe instrument tuning systems and their particularities.
106
        It may also be used to characterise a (potentially unknown) temperament that was used when tuning an
107
        instrument for a particular performance or recording. <br><br>
108
        At this stage the ontology is far from exhaustive. We primarily deal with
109
        temperaments in western tonal music with an emphasis on tuning keyboard instruments.
110
        One important objective is to be able to describe arbitrary temperaments,
111
        or express the results of automatic temperament extraction from audio recordings.
112
        </p>
113

    
114
    <h3 id="s11">1.1 About instrument tuning</h3>
115

    
116
    <p>Tuning an instrument consists of choosing the frequency values and spacing (or ratio) of pitches that are used.
117
        Pure (just) intervals of pitches correspond to whole number ratios of their frequencies, however
118
        these ratios are not compatible with each other as they arranged in scales (the way octaves are divided into discrete pitch classes) in western music. 
119
        For example, it is not possible to fit twelve pure fifths (3:2)^12 into seven octaves (2:1)^7. The difference
120
        is called the Pythagorean or Ditonic comma (23.5 cents). This difference has to be
121
        tempered out ---that is, some (or all) fifths has to be mistuned slightly in order to
122
        fit them. There are many tuning systems. Most commonly, they differ in the way they compromise
123
        pure intervals to solve this problem. </p>
124

    
125

    
126
    <h3 id="s12">1.2 An open-ended temperament description model</h3>
127
        <p>There is no mutual agreement in the literature on the description or classification
128
        of temperaments. Therefore, in this ontology we do not impose a 
129
        hierarchy between types of temperaments. We define an opaque
130
        top-level temperament concept. Subclasses of this concept can be used
131
        in describing individual temperaments, if necessary, using multiple class memberships.
132
        Since there is more than one way to associate tuning systems with their properties, 
133
        we treat temperament descriptions as concepts as well,
134
        and use reification to keep the model open and extensible.</p>
135

    
136
        <p><center><img src="TemperamentDescription.png" alt="Using the Circle of Fifths to describe a temperament." width="850">
137
                <br><br>Figure 1. Overview of the temperament ontology.</center></p>
138

    
139

    
140
    <h3 id="s13">1.3 The many ways of describing temperaments</h3>
141

    
142
    <p>Temperaments can be characterised in lots of different ways. 
143
        The most common methods are using either the circle of fifths or
144
        give the pitch deviations from equal temperament. We define these
145
        descriptions as concepts in the ontology, however, other descriptions
146
        may be used and defined in the future. 
147
        (For example, one might find it convenient to express the same information using the circle of fourths.)</p>
148

    
149
    <h4 id="s131">1.3.1 The Circle of Fifths</h4>
150
        The circle of fifths has several uses in music theory. 
151
        It shows the harmonic relationships of the twelve major and minor keys.
152
        It can also be seen as a circle of the corresponding pitch class intervals,
153
        such as (C-G), (G-D), (D-A) etc... If we go around the circle using pure fifth 
154
        intervals, it wouldn't close. What remains is the Pythagorean comma.
155
        Hence, it is often used to describe temperaments by showing how 
156
        the comma is distributed among the intervals to close the circle.
157
        (Note that there are several types of commas related to different 
158
        tuning problems. These are defined in the ontology.)
159

    
160
        <!--<p><center><img src="CircleOfFifths.png" alt="Using the Circle of Fifths to describe a temperament." width="350"></center></p>-->
161

    
162
    <p>...</p>
163

    
164
    <h4 id="s132">1.3.2 Deviations from Equal Temperament</h4>
165

    
166
    <p>In equal temperament an octave is divided into twelve equal intervals. 
167
        As a result only octaves are pure. All other intervals are impure, and the 
168
        deviation from pure is different in case of each interval. Since equal temperament
169
        has become very common, other temperaments are often described by
170
        the frequency deviations (in cents) of each pitch class from the 
171
        corresponding pitch class in equal temperament.</p>
172

    
173
    <!-- ===================================================================== -->
174

    
175
    <h2 id="sec-glance">2. Temperament  ontology at a glance</h2>
176

    
177
    <p>
178
      An alphabetical index of Temperament  terms, by class (concepts) and by property 
179
      (relationships, attributes), are given below. All the terms are hyperlinked 
180
      to their detailed description for quick reference.
181
    </p>
182

    
183
    <!-- The list of classes and properties goes here -->
184
    %s
185
    <!-- End of the terms list -->
186

    
187
    <p>...</p>
188

    
189
    <!-- ===================================================================== -->
190

    
191
    <h2 id="overview">3. Temperament  ontology overview</h2>
192

    
193
    <!--<p>The Temperament definitions presented here are ...</p>-->
194

    
195
    <h3 id="s31">3.1. Example</h3>
196

    
197
    <p>Here is a very basic example describing a pitch class interval in the Valotti temperament using the circle of fifths.</p>
198

    
199
    <div class="example" style="white-space: pre-wrap;">
200
      <pre>
201
                @prefix rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;.
202
                @prefix rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;.
203
                @prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
204
                @prefix tm: &lt;http://purl.org/ontology/temperament/&gt; .
205
                @prefix pc: &lt;http://purl.org/ontology/temperament/pitchclass/&gt; .
206

    
207
                :ValottiTemperament a tm:WellTemperament;
208
                        tm:description :ValottiDescription1 .
209

    
210
                :ValottiDescription1 a tm:CircleOfFifths;
211
                        tm:interval [
212
                                a tm:FifthInterval ;
213
                                tm:deviation [
214
                                        a tm:IntervalDeviation ;
215
                                        tm:comma tm:PythagoreanComma ; 
216
                                        tm:value "-0.16667"^^xsd:float ;
217
                                        rdfs:label "-1/6"
218
                                        ] ;
219
                                tm:lower pc:C ;
220
                                tm:upper pc:G ] ;
221
                        tm:interval [ # the rest of the intervals on the circle of fifths 
222
                                ] .
223
      </pre>
224
    </div>
225

    
226
    <p>A graphical representation of a similar description is shown in figure 2.
227
        We explicitly name the pitch classes involved in each interval on the circle of fifths. 
228
        The IntervalDeviation concept describes the amount of deviation from a pure interval
229
        in terms of a specific type of comma and a corresponding value (a fraction of that comma).
230
        We can safely assume that a fifth is pure, unless the deviation is given.</p>
231

    
232
        <p><center><img src="CircleOfFifths.png" alt="Using the Circle of Fifths to describe a temperament." width="350">
233
                <br><br>Figure 2. Describing temperaments using the circle of fifths.</center></p>
234

    
235

    
236
    <!-- ===================================================================== -->
237

    
238
    <h2 id="reference">4. Cross-reference for Temperament  classes and properties</h2>
239

    
240
    <p>...</p>
241

    
242
    <!-- The following is the script-generated list of classes and properties -->
243
    %s
244
    <!-- End of the terms list -->
245

    
246
    <p>...</p>
247

    
248
    <!-- ===================================================================== -->
249

    
250
    <h2 id="references">A References</h2>
251

    
252
    <dl>
253
      <dt class="label" id="ref-some">Music Ontology</dt>
254
      <dd><em>The <a href="http://purl.org/ontology/mo/">Music Ontology</a></em> is a thorough and mature ontology for describing
255
                music-related data, including musicological information. This ontology is intended to be
256
                used in conjunction with the Music Ontology.</dd>
257
    </dl>
258

    
259
    <!--
260
    <h3 id="references-other">A.2 Other references</h3>
261

262
    <dl>
263
      <dt class="label" id="ref-rfc2119">IETF RFC 2119</dt>
264
      <dd>
265
        <em><a href="http://www.ietf.org/rfc/rfc2119.txt">RFC 2119: Key words
266
        for use in RFCs to Indicate Requirement Levels</a></em>. Internet
267
        Engineering Task Force, 1997 (see http://www.ietf.org/rfc/rfc2119.txt).
268
      </dd>
269
    </dl>
270
        -->
271

    
272
    <!-- ===================================================================== -->
273

    
274
    <h2 id="changes">B Changes in this version (Non-Normative)</h2>
275

    
276
    <ul>
277
      <li><p>first published draft 18-12-2009</p></li> 
278
    </ul>
279

    
280
    <h2><a id="acknowledgements"></a>C Acknowledgements (Non-Normative)</h2>
281

    
282
    <p>Some modelling concepts in this ontology were borrowed form the
283
        <a href="http://purl.org/ontology/chord/">Chord Ontology</a></em>
284
        and the 
285
        <a href="http://purl.org/ontology/similarity/">Music Similarity Ontology</a></em>.
286
        </p>
287

    
288
  </body>
289

    
290
</html>
291