Understanding Arsis and Thesis in Music

James Thurmond’s book Note Grouping changed my life. It is a very small book (it can be read in around an hour), but its principles and brilliance last long after you finish the last page. Since reading this book several years ago, I have never looked at music in the same way.

Thurmond describes the concept of Arsis (upbeat) and Thesis (downbeat) in music. He takes these terms from the ancient Greeks, who used the raising (upbeat) and lowering (downbeat) of the foot for the timing of the Greek chorus.

By emphasizing the notes on upbeats (in a 4/4 measure this would be the second and fourth beats of the bar) the performer gives greater momentum and forward motion to the musical line.

Greater expressiveness requires this emphasis on the upbeat or Arsis. It can be done either by lengthening the note somewhat OR by stressing it dynamically. When music STARTS on a Thesis/strong beat, there is always an understood Arsis. For the singer, this Arsis is the intake of breath – which should be taken rhythmically and expressively in anticipation of the sung text.

An example of Thesis (T) and Arsis (A) in music in relationship to the strong and weak beats of the measure.


Many times singers are told to sing with ‘more line’ or ‘more legato’ but aren’t told in most cases how to accomplish this. A singer that understands Arsis and Thesis in music making can render any song in a musically ‘moving’ way. The singer can break apart the music, understanding the ebb and flow of every phrase, and give each an expression that far outpaces ‘singing the notes.’

When you understand Arsis and Thesis, you begin to understand that the arrangement of upbeat/downbeat reflects so many patterns of duality in our lives. The first act of life is an intake of breath (Arsis). Our last act here is the final sigh of death (Thetic). Everything that comes between is the music of our lives.

In popular and contemporary music, there is a very strong emphasis on the FIRST and THIRD beat. This is in no small part due to the fact that much of this music is connected to dance forms, which require a highly distinct pulse. Classical music requires a different approach to rhythm.

Musical notation exists for ease of READING and is structured from Strong (Thetic) to Weak (Arsic) structure. However, note grouping requires the singer to re-group what they see into more cohesive patterns (Arsis/Thesis). Written in an Arsis/Thesis structure, it would be very difficult to read.

Arsis/Thesis can lead the way to more successful music making, and performances of rare expressive and emotional quality.

In a future post, I will explore Arsis/Thesis within the framework of a classical aria and a musical theater song. The reader will gain a greater understanding of how their inherent musical properties can be brought out from a rhythmic perspective and lead to more expressive performance.