The truth is that we *should* have 17 notes per octave in our occidental musical system. Bach and his son always demanded a 17-key piano and there acutally are some of those where the black keys are split, but hardly anyone knows about them let alone knows how to use them. Why?

well - music nowadays is much more emotionless thanx to todays tuning (look that up in my instructos section). this is a very long story and i will write it down and share it with you some day - right now i´m not realy allowed to. however...
remember that i told you once, that a good violinist will tell you that he plays an F sharp for example slightly different than a G flat? if you play classical music the way it should be played you HAVE to do it that way. an F sharp used to be a differnt note than a G flat. even the blue note did exist back then. they are not a creation of the bluesfolks as most peeps think - they have been in existance for centuries - evne the ancient greek had them! so if you want to play bachs music the way he wanted it to sound, then you have to have a copy of the ORIGINAL handwritten score and play all the sharps slightly higher and all the flats slighly lower. if you do this correctly the music REALY comes to life. a chord with those notes in it doesnt sound as "sterile" as it does with our regular tuning. it comes to life - it BURNS!

But thanks to folks like Jean Phillipe Rameau or J. Mathesson we have lost this knowledge and we have a music-theory thats filled with inconsistancies that hardly anyone fully understands and students all over the planet have a hard time getting the hang of it (just look at all the questions and the hyper-complex answers in this forum).

however - this specific guitar looks more like it is tuned to some exotic scale for i have seen guitars with 17-note-per-octave frets and they look different to this one. looks as if the frets of a Saz or something like that have been adapted to this guitar.