A piano chord is a combination of three or more notes played simultaneously. The most common types of chords are major, minor, diminished, and augmented. Each chord has a unique sound and emotional quality, which can enhance the music being played. Chords are built on a specific note, called the root, and include other notes that are spaced at certain intervals. Chords are essential in various music genres, including classical, jazz, and pop. They provide harmony and support the melody, creating a fuller sound. Musicians often use chord progressions, which are sequences of chords, to structure their compositions and evoke different feelings in the listener.