Melody/Harmony

Acciaccatura

An ornament which sounds like a crushed note played very quickly on the beat or just before it.

Added 6th

For example

C E G A

Diminished 7th

For example

E Eb F# A

Diminished Triad

Moves down a semitone.

Dominant 7th

For example

C E G Bb

Harmonic minor scale

Sounds middle eastern.

Melodic minor scale

Changes on the way back down.

Interrupted cadence

In a major key, chord VI is minor.

Sounds unfinished.

Interval

The distance between 2 notes.

Mode/Modal

Usually refers to any of the early scales (Dorian = White notes D to D)

Mordent

An ornament consisting of the main nite, the note above, the main note.

Obbligato

A prominent solo instrument part in a piece of vocal music.

Plagal cadence

Chords IV to I at the end of a phrase.

Sounds finished.

Relative major.

The major key with the same key signature as one minor key.

Relative minor.

The minor key with the same key signature as one major key.

Tierce de picardie.

The final chord in a minor key is changed to major.