E: The key of E.
Eighth: An octave.
Elegy: A melancholy piece.
Eleventh: The interval of eleven diatonic degrees.
Embellishment: ornaments added to music to make it more interesting.
Ensemble: A group of singers, or instrumentalists.
Equal Temperament: Any tuning system which divides the octave into equal intervals.
Ethnomusicology: The study of various types of music in relation to their geographic, racial, and cultural context.
Etude: A short song, usually written for pedagogical or instructional use.
Even Tuning: See equal temperament.
Excercise: A short piece written to improve performance technique.
Expressionism: An early 20th-century musical style, employing an abstract approach to music, unlike impressionism.