Cousin to the regular 7 chord
To illustrate these chords I wrote a little tune for the LH to practice them in root position along with a simple melody.
Here are ways you will see these chords notated as symbols:
- X maj7
- X M7
- X MA7
- X Ma7
- X maj
X maj7 is most common most clear.
Take a regular 7 chord, then change (b)7 to maj7. There is close to zero problem with spelling, because it is beyond rare to see it written more than one way in notation. Before around the end of the 19th century, it was extremely rare to end a piece of music with Xmaj7. Starting with Debussy and his contemporaries, this change, and it is extremely common today in jazz and pop.