He was using electronic/synthesised orchestral sound to try and create "classical" music. While it absolutely not well written concert music, basically a lot of repeating of themes instead of developing it.
At least the theme sounds somewhat melodic and it was a nice respite than this nonsense RnB/funk/soul stuff that he normally writes.
The only Prince album worth getting is
Purple Rain 12/15
The rest of his discography is less than 8/15
In fact I think he only has one song outside Purple Rain that is good. Which is "If I Was Your Girlfriend" that is surprisingly melodic