Agreeing, 6 letters
Coinciding, 6 letters
Consonant, 6 letters
Harmonious, 6 letters
Harmonized, 6 letters
Harmonizing, 6 letters
How Joey Fatone's band sings?, 6 letters
Jibing, 6 letters
Matched precisely, 6 letters
On the same page, 6 letters
On the same wavelength, 6 letters
Simpatico, 6 letters
Simultaneous, 6 letters
Together, 6 letters
Together, as a picture and a soundtrack: 2 wds., 6 letters
Unlike some YouTube videos, audio-wise, 6 letters
Well-coordinated, 6 letters
Well-harmonized, 6 letters
Working perfectly together, 6 letters
Working together, 6 letters
Working together perfectly, 6 letters
Working well together, 6 letters