A major six-nine chord is composed using a root/1st, major 3rd, perfect 5th, major 6th and major 9th (or R/1-3-5-6-9) intervals played simultaneously. Generally written as C6/9 or Cma6/9, it is good practice to simply use an uppercase C followed by a super scripted 6/9 to represent it in writing (ie: C6/9).
Major six-nine chord profile
|Intervals||root/1st, major 3rd, perfect 5th, major 6th, major 9th or R/1-3-5-6-9|
|Common names (examples in C)||C6/9, Cma6/9, Csix-nine|
|C Major six-nine chord voicing #4|