Essential Principles and Types of Musical Form

Principles of Formal Composition

The fundamental principles governing formal composition include:

• Repetition
• Sequence
• Variation
• Development
• Contrast

Classification of Musical Forms

Forms Classified by Performance

Musical forms are categorized based on the performing forces involved:

• Vocal Forms: The voice intervenes, with or without instrumental accompaniment.
• Instrumental Forms: Composed specifically for instruments.

Forms Classified by Structure

Musical forms are also categorized based on their internal structure and duration:

• Simple or Minor Forms: Made up of a single movement or a short duration.
• Compound or Major Forms: Made up of several movements or a long duration.
• Free Forms: Those which are not subject to any strict structural rules.

Major Vocal Forms

The Song

The song is a vocal composition written on a text. It is a simple vocal form, consisting of just one movement.

The Opera

The opera is a theatrical play entirely set to music. It utilizes a compound vocal form which consists of several movements. Characters participate by singing as soloists or in a choir.

The Oratorio and The Mass

These represent the greatest forms of religious vocal music. Both are compound forms characterized by long duration and several movements.

• The Oratorio: Can be understood as an opera with a religious subject, although it does not include a stage performance.
• The Mass: The result of putting together the different prayers that form the liturgy.

Instrumental Music Forms

Dance Music

This category includes dance theater (or ballet) and social dance, which gave rise to ballroom dance and today's urban dance.

Compound Instrumental Forms

The Concerto, Sonata, and Symphony are compound forms that use common composition schemes. They are primarily differentiated by their instrumental formation:

• The Concerto is typically written for soloists accompanied by an orchestra, or for the orchestra itself.
• The Sonata is usually intended for a soloist instrument (often with piano accompaniment) or a small ensemble.
• The Symphony is a large-scale work for orchestra.

Simple Instrumental Forms

These are simple forms or independent compositions, usually intended for a soloist instrument.

Simple Structural Forms

Simple forms can be written for voice or for instruments and consist of just one movement or are of a short duration.

Primary Form

This form consists of a single musical phrase or section which is repeated. Examples include the Romance and the children's repertoire. The Canon is also a primary form because it consists of the repetition of the same phrase by overlapping the entries at different times.

Binary Form

Binary form consists of two different musical phrases or sections that are usually repeated. It can be presented alternately, like a song with verses and choruses (e.g., ABAB), or it can appear consecutively (e.g., AABB). Common presentations include AABB and ABAB.

Ternary Form

Ternary form consists of three phrases or sections. The third section is usually the repetition of the first one (also known as Da Capo, or ABA). We can also find ternary forms in which all three sections are different (ABC). Common presentations include ABA and ABC.

Rondo Form

Rondo form consists of a main theme (A) which contrasts along the piece with new sections (B, C, etc.) and is repeated between each of them (e.g., ABACA).

Themes and Variations

The composer presents a theme and then repeats it along with some modifications. The variations of the theme can be achieved by manipulating elements such as:

• Melody
• Tonality
• Rhythm
• Texture
• Timbre