The study of musical expression is a lifelong process.  Once one masters the basics of musicianship and is able to reproduce musical notation accurately and in tune, the most important ingredient in musical performance, expression, remains to be mastered.

There are probably as many ideas about musical expression as there are conductors and performers.  At one level this is all right, because intuition, for example, does have a place in musical expression.  It is only when intuitive performance ignores musical nuance and performance practices that it often strays into the realm of anachronistic performance (i.e., using Romantic era performance ideas to perform Bach).

Expression markings added to modern scores are helpful.  Variations in dynamics, phrase markings, accents, articulation signs, etc. all provide great helps for the performer in making decisions about musical expression.  Nevertheless, score markings alone cannot communicate all of the subtle details about musical nuance, about the ebb and flow of musical phrases, or about how note "A" relates exactly to note "B" and then to note "C" etc.  Moreover, when approaching music written before 1750, precious few score markings exist at all unless added by an editor.  [For more information see Choosing a Good Edition.]

Hidden within the notation itself, however, are valuable hints and organizational tools for the conductor and performer.  They consist of inherent tendencies that allow certain notes within a musical context to be stressed, accented, or singled out as major or minor goal points of the melody or musical phrase.

If we agree that music is always in motion, moving toward or away from goal points, determining the goal point or points within a complex musical phrase must be a starting place for every conductor or performer.  Musical accents are often discussed in beginning theory classes only soon to be forgotten and probably never actually connected to their value in understanding musical phrasing.

Since the word "accent" may suggest to some a striking of a note and quickly backing away, calling these inherent tendencies rather by the word "stresses" provides a broader term that would allow for a much wider variety of musical approaches in realizing goal points than the former term would seem to convey.

Metric stress - inherent in music organized by meter with the primary and/or secondary stress points (i.e., beats 1 & 3 respectively in 4/4 time)

Agogic stress - (duration stress) inherent in notes of longer duration than those around them

Tonic stress - (pitch stress) in which the highest and/or lowest notes within a phrase receive an inherent stress

Harmonic stress - inherent in the dissonance/resolution or unstable/stable harmonic sequences

Weight stress - achieved through texture or volume of sound rather than intensity of sound

Pattern stress - inherent in repeated patterns of a common musical shape

Embellished stress - inherent in notes that are embellished melodically with appoggiaturas, acciaccaturas, mordents, trills, etc.

Syncopation stress - inherent in this formula that shifts stress to the off beat and is more pronounced when approached by a short note or a note articulated short

Great composers of choral and vocal music will usually find ways to make sure that "word stresses" (inherent in various languages) are reinforced by one or more of the notational stresses mentioned above.  When they don't seem to match, one should look to see if the text being used is a translation or adaptation.  Regrettably, many translations have not been devised with the same care one will find in the original setting.

Discovering the inherent stresses in a musical score can be an enlightening experience.  It can also help sort out some complexities where competing stresses may call for more than one approach to various voices within the musical texture.

Discovering the inherent stresses is the starting point for understanding musical phrase.  For no two musical notes are the same.  No two rhythmic pulses are exactly alike.  Music is always moving toward or moving from goal points.  Each note has its dramatic meaning within the musical phrase because of it distance (near or far) from the goal.

Goal points within the phrase structure, then, usually are reinforced or identified by the convergence of more than one notational stress indication.  When doubt arises, look for the weight of evidence.  At what points do several notational stress indicators converge?  (Don't forget to include "word stresses" and "dynamic score markings:  >, sf, sfz, etc." into the mix.)  Normally, this determination will provide the "secret" information needed to perform the phrase with confidence as well as providing an informed structure on which to base your musical decisions.