Primary sources in music mean that they are a direct representation of the work of the composer or author. This is different than secondary sources—books and journal articles—which often analyze primary sources. And tertiary sources—encyclopedias and dictionaries—are often research done on secondary and primary sources.
A primary source is an original work. Types of primary sources include:
Secondary sources are one step removed from primary sources. Often they are an analysis, critique, or interpretation of a primary source.
Types of secondary sources include:
Tertiary sources are often a combination and examination of primary and secondary sources. Examples include:
| Primary | Secondary | Tertiary |
| Letters by John Cage | A website about Cage's writings | An encyclopedia on experimental music |
Source Readings in Music History by 
Music in the Western World by 
Music Education: Source Readings from Ancient Greece to Today by 
Women in Music by 