Friday, June 9th, 2023

Barlines – Music Theory – Part 14


A Tonal System

Scales in Music – A Tonal System

Music Theory Section – Level 1

Barlines – Part 14


Measures in music are created using barlines to produce them. In Part 14 of the Scales in Music – A Tonal System article series and within the Music Theory Section – Level 1, barlines play an important role in determining the end of a section of music, for delineating or marking off measures of music and for the final ending.

Barlines – Part 14 is no where near as complicated as others simply because there are only three basic concepts within this article and all are part of basic music theory. The first of these ideas will follow immediately hereafter.

There are no prerequisite articles to refer to with the exception of The Grand Staff however you will find this article about barlines fairly easy to understand although it is important information to know for music notation.  The musical staff is so fundamental to music and the very basic idea of barlines make up the musical staff. It is so basic and rudimentary that barlines are used throughout the entire article series on Scales in Music – a Tonal System.

Making the Staff

There is a specific set of barlines called staff lines and they are the five lines which form the basis of the musical staff. This was discussed in detail in the article The Grand Staff – Music’s Secret Stairway. Please review that article if you need clarification.

Barlines - Lines OnlyThe chart simply shows the five lines and the four spaces that make up the staff. It is the most basic of the concepts in music notation.

Making Measures

Barlines – Single Barlines – Barlines are simply the thin vertical lines marking off a measure. Barlines are not the measure themselves rather they are the dividing line between adjacent measures within the composition. The next chart shows the vertical line or barline on a five line four space musical staff as it is used today. It is simply a thin vertical line which starts on either the top staff line or the bottom staff line and passes through all the internal staff lines as shown below.

The Vertical (thin) Barline

Barlines - Basic StructureOne Measure – The next chart shows one complete measure marked off by two vertical barlines. The space in between two barlines is called a measure. The barlines themselves are not the measure they are only the boundaries to the measure.

Single Staff - Measure

Barlines – Double Barlines – Double barlines are similar with respect to single barlines in so far as they are made up of thin vertical lines. This time there are two thin barlines placed close together on the staff shown in red in the chart below.

Two Verticle Lines - Section BreakThe double barline performs a completely different function than a single barline. The double barlines purpose extends beyond simply marking off the measure. It is used to mark off the end of a passage or section of music rather than simply the end of the measure although they fulfill that function as well.

Barlines – The Final Ending – One last barline in this presentation is the final barline. It is the tool used to mark off the final ending of the music composition. The chart below shows the final ending symbol.

Measure Marks - Finale

In the above chart marked in red, we see a single thin barline followed by a single thick barline marking off the boundary on the right of  the final measure. This is the method and symbol used to end all musical compositions regardless of the genre or style of music. When the performers reach this point in the score, the music stops and hopefully the applause begins!


There are two types of barlines, those that are classified as staff lines and those called measure lines. Each performs its own function and together they create the musical staff.

Single vertical barlines mark off the measures. They are not the measure rather they are the boundaries to the measure.

Double barlines mark off the end of a section of music. The performer continues  playing through and they know they are now in a new passage or section of the music.

The final ending barlines are used simply to end the composition. All performance stops once the players reach this point in the composition.


There are many more types of barlines to present which fall into different classifications and they perform different functions. Up next we will explore the first classification called “repeats”. This is the subject matter of the next article within this music theory – level 1 series of articles.

See, I told you that there were some concepts that were very easy to understand and the barlines is one of them.

This concludes Barlines – Part 14 of the music theory section – level 1 of the overall series of articles included in Scales in Music – A Tonal System.

Up Next

The next article in the music theory series is called Repeats  – Music Theory – Part 15a. Part 15a begins our 4-part mini-series on repeats as used in music notation.

Due to the length of the overall article on repeats we have split it into four parts. The articles are listed below with links directly to each. Otherwise please follow the link for Part 15a at the bottom of the list.

In 15a we will present various types of repeats, their symbols and their meaning, as related to symbols on the staff.

In Part 15b we will present the wording and additional symbols used primarily on the staff to direct the performers on where to go to begin a repeat and where to follow after the repeat begins. First and second endings are also presented.

In Part 15c we will present information about the words used to navigate a score and discover the Coda and Finale.

In Part 15d we will look at the symbols and their meaning to repeat notes, rests and measures.

Please proceed to Repeats – Music Theory – Part 15a.

Mini Series Links

To return to the Music Theory – Level 1 directory for the article listings within the series, please proceed to Music Theory Section – Level 1 – Series Introduction – Part 10.

To continue onto Music Theory – Level 2 directory for the article listings within the series, please proceed to Music Theory Section – Level 2 – Series Introduction – Part 20

To proceed to Acoustics of Music directory for the listings within the mini-series, please proceed to Acoustics of Music – Part 1 – Series Introduction.

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