Counterpoint consists of simultaneous contrasting melodies.

The aim of counterpoint is contrast. Counterpoint creates harmony through the interaction of two or more melodies which differ from and contrast with each other.

Counterpoint is taught in a form known as species counterpoint or strict counterpoint. There is some debate whether species counterpoint is a standalone approach to writing music or whether it is a learning tool. Whatever it is, it is still widely taught today in universities and colleges.

Species counterpoint was documented in 1725 by Johann Joseph Fux in his book Gradus Ad Parnassum. It is structured as a discourse between Aloysius, the venerable master, and Josephus, the keen young grasshopper student. The book is pithy, practical and eminently readable. Fux ends the Foreword with the resplendent phrase: I would rather be understandable than seem eloquent. Farewell, profit and be indulgent.

Would that all writers were so humble.

Species counterpoint is a graded approach to writing counterpoint. There are five species:

  1. First species counterpoint covers contrapuntal melody, contrapuntal consonance and contrapuntal motion. The rhythm is the same in both parts and the interval between them is always consonant.
  2. Second species counterpoint covers rhythm and dissonance. One part is in whole notes, the other in half notes. The first notes in a bar must form a consonant interval, the second note may form a consonant or dissonant interval.
  3. Third species counterpoint extends the theme of rhythm to cover four notes in one part against one note in the other part.
  4. Fourth species counterpoint extends the theme of dissonance to cover overlapping notes in which the first beat in a bar may be consonant or dissonant while the second beat is consonant.
  5. Fifth species counterpoint introduces no new material and collates the first four species into a single form.

This section provides all the tools necessary to write counterpoint. Most of it concentrates on writing counterpoint in two parts. Multipart counterpoint is covered at the end along with some ideas for orchestration.