Lawrence, not by the wildest possible stretch of the imagination could your Requiem Solina Polara be seriously classified as "jazz". It is definitely "New Age" and could possibly cross over into the realm of "experimental". In fact, the ping-ponging synthesizer track, which plays throughout the composition as a kind of "drone", with a hypnotic repetitive quality, actually fits part of the definition of New Age music as provided by Wiki: "The melodies are often repetitive, to create a hypnotic feeling, ....New Age music includes electronic forms, frequently relying on sustained synth pads or long sequencer-based runs....." etc.
Like music of all genres, there is great New Age music and not-so-great New Age music. When the category first emerged about 30 years ago, it was regarded as fairly "cool" and innovative. Millions of people enjoyed the work of New Age music pioneer, KITARO. It was as the whole notion of "New Age" gradually got trashed by Shirley MacLaine & company and began to be associated with cults and wacko philosophies in the popular imagination that the musical genre lost credibility. These days, unfortunately, it tends to be looked down on - perhaps because it is often thought of as music specifically conceived as background for some activity OTHER than listening to music (meditation, yoga, relaxation, chanting, etc.).
There are really fine musicians who are classified today as New Age, but who were making recordings long before New Age was even a category (sitar player Ravi Shankar, Celtic harpist Alain Stivell, etc...these artists used to be classified as "Folk" or "Ethnic"). Amey is right, a lot of music ends up in the New Age bin simply because the industry doesn't know what else to call it.
For me, it doesn't matter what pigeon hole they try to force someone's music into.
"What's in a name? that which we call a rose by any other name would smell as sweet."...................or not, as the case may be.
Just as a little theremin Post Script, if I remember correctly the very first Ethervox theremin went to Masanori Takahashi (aka New Age musician, "Kitaro").