An "Altered Chord" is a type of chord used in music that includes one or more notes that have been changed from their original form. Typically, this involves altering the fifth or seventh note of a chord, often by raising or lowering it. These chords are commonly found in jazz and contemporary music, adding tension and color to harmonic progressions. Altered chords can create a sense of movement and resolution in a piece. They are often used in conjunction with dominant seventh chords and can lead to unexpected harmonic shifts. Musicians use altered chords to enhance emotional expression and complexity in their compositions.