How can a musical mode be used in a monophonic melody?

In a monophonic melody—a single, unharmonized melodic line—a musical mode serves as the essential vocabulary for construction. It provides a theoretical framework that dictates which notes are available and establishes a hierarchy of importance among them.12

To use a mode in a monophonic melody, a composer or performer typically follows these principles:

• Defining the Vocabulary: The mode specifies the available scale degrees, ensuring the melody adheres to a consistent intervallic structure.12
• Establishing Importance: Within the mode, certain pitches are given prominence. The melody often centers on a final (the note on which the melody ends) and a dominant (a secondary center of importance).1
• Melodic Shaping: Prominence is achieved by reiterating specific pitches, using them as range limits, or placing them at the ends of melodic sections or the entire piece.2
• Formulaic Construction: In many traditions, modes serve as the basis for specific melody types or formulas (such as the ancient Greek nomoi), which guide the performer in improvising or composing within established boundaries.23