Rare groove is a special kind of music that is a bit hard to find. Imagine you have a toy that nobody else has ever seen before - it's kind of like that.
Long ago, people would make music and some of it was really good but not many people knew about it. Then, other people started discovering this music and liking it a lot. But still, not many people knew about it. This made the music really cool and special because it's not like the usual popular songs you hear on the radio all the time.
Today, people still love rare groove music because it's kind of like finding a treasure. You have to look really hard to find it but when you do, it feels really special. The music is often from the 60s, 70s, or 80s and it has a unique sound that you don't hear every day. People like to dance to it and it makes them feel happy.
So, rare groove is special music that not many people know about but when you find it, it feels like you've found a really cool and fun toy.