A sixth chord
A6 chord for piano with keyboard diagram.
Explanation: The A major sixth is a four note chord. You can see the four notes marked in red color. The chord is abbreviated A6.
Theory: The A6 chord is constructed with a root, a major third, a perfect fifth and a major sixth.
Fingerings: little finger, middle finger, index finger, thumb (left hand); thumb, index finger, middle finger, ring finger (right hand).
Notes: A - C# - E - F#