This is when ear training & theory get married.
The Triad... Root, 3rd, 5th and the Octave can be used in lots of cases...
The DMaj7 will add a 7th to fill out the sound, a bit.
A good place to practice is playing Major and Minor Triads... to learn the sound they make, then start throwing in the 7th, or flattening, the 3rd
Once you begin to hear the different sounds the different patterns make, you will begin to hear them in songs. And now how to move around.