If only there was a simple definition ;-)
I've always described Music as...organized audible tones that stir emotion in the human spirit! Simple as that. All purely subjective and purely dependent on the individual listener. I for one am not a fan of most folk or country. But I'd never dare not call it music. Some people love that death metal stuff w/ that sounds like the Cookie Monster singing w/ a mouth full of gravel. Definitely not for me...but it's still music! Vai is certainly capable of creating some really sweet melodic stuff. And he is constantly pushing new boundaries in his playing. I guess it comes down to a generational gap. My father who was born in the 20's was a serious classical aficionado. He could have taught graduate courses on the subject. But, he also saw zero value in Dylan, The Beatles, Stones, Hendrix, Zep, or most of anything I was into. It was ALL noise to him.
Only time I ever perked his ears w/ music coming from my bedroom was w/ ELP's Pictures At An Exhibition. That he understood. He didn't like it, but at least he sensed a slight connection.
Here's an original tune Vai presented on his 60th birthday in 2020. Utilizing an all new multi finger bending method no one had ever seen before. No shredding here. Just painstaking labor to get to his own demand for perfection. I like it!!
and here's another video of an online guitar teacher explaining what's going on and how it floored him to witness this new technique.
Just that pic he shows of Vai's finger tips looking like they were worn to the nubs from practicing that stuff over and over and over. Mad respect!
That's pure passion....which according to my definition, deems it 100% grade A...Music!