What are Altered Chords?
Altered chords are chords that are modified or "altered" from their basic major or minor triad or seventh chord structure by changing one or more of their notes.
The alterations usually involve raising or lowering the fifth, ninth, or eleventh notes of the chord, and are used to create a more dissonant, tense, or colorful sound.
In jazz and other styles of modern music, altered chords are often used to create tension …