Rest assured, North Texas is among the very best music schools in the country. Who is "best" needs to be answered by the question, what do you want to study?
For example, Juilliard puts more people in orchestras than any other school. Rice does very well with this, also.
In jazz and popular music, North Texas and Berkeley in Boston lead the way. I would venture we have won as many Grammys as anyone.
The great strength of North Texas is that we are strong across the board; classical, jazz, keyboard, composition, whatever. There is not a weak program here. With the exception of Indiana University, I do not know of another school like ours. Our students win prestigious international competitions on a regular basis and come from all over the world to study here. There are CoM YouTube videos with over 1M views.
The other great advantage of North Texas is its cost. Here, no one can come close. I know of many, many youngsters in NYC that are graduates of Juilliard, New England Conservatory, and the like that have over 100,000 in student debt. They are hard-pressed to make 20,000 a year.
As for the rankings themselves, here they are: https://www.unt.edu/rankings/college-music.html
Personally, I wish they would go away. There is no objective data used in these and most are nonsense. If anyone thinks UT at Austin is the top music school in Texas, as rated by "Best Music Colleges.com", then I have a bag of turnips I would like to sell you.