My top artist on spotify for the last 4 years is Hiromi Iwasaki, a Japanese singer whose heyday was in the 70s and 80s. I think her voice is incredible. Many of her singles are disco-ey but also romantic and mature. I also find her original music show performances to be very charming, but most of them have been deleted from Youtube only to be uploaded again in worse quality.
★★★★☆1/2 you’ve never heard of something like that in 2018. Like very thearical like for a real lack of better exemple, it’s the musical vibes of Midori: the camellia girl.