en:advanced1 [Computergestützte Musikanalyse]

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=====Module Advanced Sheet Music Analysis with music21: Searching for Tone Sequences =====

This module explains how to search for certain patterns in a music file. 

In general, patterns are structures that occur several times. In music, there are many such patterns: melodic-rhythmic motifs, accompaniment figures, rhythms, chord progressions, and so on. Many of these patterns also occur in slightly (or more) varied forms, e.g. melodic motifs on other pitches and with additional tones, or accompaniment figures with harmonic variations. 

Repetition and variation are two of the fundamental structural principles of music. Of great interest, therefore, is the question of how the principles of repetition and variation come into play in a composition, a genre, or in the work of a composer. Here it can be advantageous to automatically search for and identify certain patterns as well as to list or mark them in the musical text. In this context, one also speaks of //Pattern Mining//. This is demonstrated in the two tutorials using two compositions by Josquin and Beethoven:
   * Tutorial [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part1_Josquin.ipynb|Jupyter_SheetMusic_Advanced_Part1_Josquin]] (Jupyter notebook; [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part1_Josquin.html|html]] preview)
   * Tutorial [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part2_Beethoven.ipynb|Jupyter_SheetMusic_Advanced_Part2_Beethoven]] (Jupyter notebook; [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part2_Beethoven.html|html]] preview)


| The interactive program [[en:Interaktive Musikanalyse| Interactive Music Analysis] offers a quick and easy entry into the possibilities of computer-aided music analysis with //music21//. There you can get to know several possibilities of searching for tone sequences by selecting options, without having to get involved in the command syntax of //music21// and the functionality of the //Jupyter Notebooks//. (Prerequisite is the installation of //Anaconda// or //Miniconda//.)// |

In this introduction, the topic of pattern search is first narrowed down. 

==== Searching for melodic motifs or melodic accompaniment figures (melody cells) ==== 
The simplest and already very productive search option is the 
  * Search for certain **pitch sequences** (without duration values).

If you add the rhythmic structure (i.e. with duration values), you get a 
  * search for melody cells as **rhythmic pitch sequences**. 

These two search options are possible with //music21// and are described in the first tutorial 
[[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part1_Josquin.ipynb|Jupyter_SheetMusic_Advanced_Part1_Josquin]] (Jupyter notebook; [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part1_Josquin.html|html]] preview) in detail, using a mass composition by Josquin as an example. 

Besides searching for //identical// cells/patterns, there are several options for a //fuzzy search//: 
  * Search for **interval sequences** or for chromatic transpositions of a melody cell. 
  * Search for diatonic transpositions (within a key, i.e. individual intervals are changed).
  * Search for variations where individual tones or intervals or duration values of the melody cell are changed.
  * Search for variations where additional tones are inserted or missing. 

In //music21// only the first of these //fuzzy// search possibilities can be realized reliably, whereby the path via transpositions must be chosen. It is described in the [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part2_Beethoven.ipynb|Jupyter_SheetMusic_Advanced_Part2_Beethoven]] (Jupyter notebook; [[https://analyse.hfm-weimar.de/jupyter/Jupyter_SheetMusic_Advanced_Part2_Beethoven.html|html]] preview). \\ 
A search for interval sequences is possible with the CAMAT tool in a quite simple way, see [[en:advanced_camat#tutorial_4suche_von_intervallfolgen |module Advanced Note Analysis with CAMAT]].

The **input** of the search query in //music21// is entered as a melody cell in an easy to learn note syntax. 

The **output** of the search results is given as a list (voice, bar and bar position as the beginning of the pattern searched for) or is labelled in the score, which can be viewed in part in the browser as well as in full via //MuseScore//.

//The search is of course also possible within several pieces: A narrowing of the search corpus can be made according to various criteria, including composer, genre and period.//
==== Deepening ====
 
Search possibilities for melodic motifs in different music corpora are offered by the [[http://themefinder.org/|Themefinder]] by David Huron as well as by 
[[https://scoresearch.musiconn.de/ScoreSearch|Musiconn Score Search]] of the Bayrische StaatsBibliothek. 

The research projects [[https://jazzomat.hfm-weimar.de/|Jazzomat Research Projects]] and [[http://dig-that-lick.eecs.qmul.ac.uk/|Dig That Lick]] developed tools for online searching of the same and similar patterns in jazz improvisations (the //Weimar Jazz Database// and the //DTL1000 Dataset//): [[https://dig-that-lick.hfm-weimar.de/similarity_search|Similarity Search]].