Tutorial Sheet Music Advanced Part 2: Motif Search in a String Quartet by Beethoven

(version 2022_01_03)

This tutorial explains how to refine the motif search to search not only for sequences of notes, but for sequences of notes with a specific rhythm.

The tutorial follows on from the "Tutorial Notes Advanced Part 1: Motif search at Josquin". The first steps are therefore identical. However, we have chosen another music example: a composition by a composer in whom the use of motifs plays a particularly important role: the first movement of the String Quartet Op. 18, No. 1, by Ludwig van Beethoven.

In order to search for repetitions of the opening motive in exactly the same rhythmic structure, the melodic pattern must now be defined in rhythmic terms as well:

As expected, the motif appears relatively often: exactly 13 times!

Determining the exact position in the score (measure, beat, voice):

Marking in the score - we take the prominent position in M. 179-181, which appears in several parts at once:

Unfortunately, Beethoven very often did not notate the beginning of the motif as dotted crotchets, but rather as tied crotchets + eighth notes. Unfortunately, this notation is not included in the 13 search results.

To take these tied notes into account, a trick must be used in music21:

The command "stripTies" replaces two tied notes with a note of the same length. By this method, the motifs with overtied note values can now be determined.