In what context(s) is the Nashville Numbering System preferable to Roman numerals?

Question

In his answer to What's the difference between the Nashville Number system and a Roman Numeral System?, Dom states that "Roman Numeral Analysis as stated is used mainly in analysis while the Nashville number system is more for practical purposes." He goes on to say that the NNS makes inversions a bit more intuitive (5/7 for a first-inversion V chord, instead of V⁶), but that chromatic chords are easier in Roman numerals.

Based on the above information, the NNS would be best suited for completely diatonic music, which is relatively uncommon in popular music (the repertoire for which the NNS was devised). Furthermore, it seems odd that a main selling point is inversions, when figured bass has worked just fine for centuries.

So in what context(s) would one prefer the NNS over Roman numerals?

Answer 1

NNS was developed before the fact, while RN was developed after the fact.

As in, the purpose of NNS is to provide accompaniment in whatever key, to any songs to be recorded that would suit the singer's key, thus saving time re-writing the harmonies.

RN is far more an academic analysis of already existing music, in order to analyse what has already happened - maybe hundreds of years ago, in order to provide exact notation (explanation) of the music.

As far as inversions go, that's not so important in NNS, but is of paramount importance in RN. the two aren't really comparable from a lot of standpoints, although they appear to do similar jobs.

Answer 2

I've always believed that the Nashville system was devised to accommodate musicians with little or no ability to read roman numerals or sheet music. Country music has often utilized musicians who can play up a storm, but have little or no formal training and can count from 1 to 10 but had little or no exposure to Roman Numerals. In my own experience both systems have been used interchangeably and I haven't noticed any important difference.