More often than not, the producer already has tracks. So, if a rapper is trying to find lyrics to go with his song, it doesn't always work that way. A lot of times people ask what comes first, the chicken or the egg, or the music or the lyrics?
Usually, the music comes first because the rapper is inspired by the music. The music brings out the lyrics because, in a sense, the rapper is another instrument on the beat. So, by having the beat first, the rapper then puts its lyrics or its instrument to that beat. So, that is why you won't find that the lyrics come first. It's the beat that comes first.
But there are times that you will have the lyrics and you will try to find a beat that goes with your lyrics. Alright? So, when you're looking to match the lyrics to a track, what you want to do is find tracks that embody the feel or the vibe of the lyrics that you may have.
If you're writing about a heartfelt song to a girl or someone that passed away, you're not going to put that on a party track. You're going to put it on a track that really speaks to the feeling, or the emotion, that you're trying to convey in that rap song.
If you find the beat first, you have to listen for the emotion of that track and the vibe of that track to match your lyrics to the same feeling that that track emotes. And that is how you match lyrics and a beat together.