Answer:
I am not sure what you are trying to get at here, but I'll give it my best. First of all, if you are playing the music you are reading, you should read it at the rate you can play it at. But you cannot read music like you can read a book. The words in a book are just there to be instantly made into sentences by your brain. But music has notes, and you have to become familiar with these notes, not just expect them to make sense like words on a page do. If you are looking at the music and reading it to see what it will sound like, find a tempo and if you know with that is, then sing, tap, or hum it. If you are not caring about the tempo, then just work on keeping a steady rhythm and practice getting faster and faster. I'd say the key is keeping a steady beat. And practice and u'll get better at reading and fast reading music.