This is a helpful jazz guitar voicing for a Major 9th chord. This is a movable voicing with the root on the 5th string, meaning that you can change the letter name of this chord by moving it up or down the neck.
On the left is the Cmaj9 chord shown with the chord tones/intervals used, and on the right is the recommended finger pattern.
This chord can be used for any major 7th type chord you come across. Whether it calls for Cmaj7, Cmaj9, or anything else with a “maj” in the chord symbol, this chord will work.
In order to be able to use this chord in your playing, all you have to do is learn the notes up and down the 5th string.
Try playing this chord around the cycle of 4ths to help you learn the notes on the 5th string:
And if you really want to be able to use this chord in your playing, try this:
I find this approach to be useful for helping you get a new chord shape under your fingers in a way that you can actually use it when you need it on the fly.
Whether you’re playing through the Real Book, or sitting in a jazz ensemble, this is a good way to learn new chord vocabulary as you play.