Hi,

I am sharing my own method recently used in Japan on May day. We were suppose to sing some part of "We are the world" in various languages. (we paid royalty fees to sing a copyrighted song. Japan is strict in copyrights).

Ok if you use Music Maker on arranger you will have your audio when you will zoom it you can see up and down of beat in the graph. The best thing is to use Head phone. Play music, now start singing, use watch to adjust your timing to be with the music.
When you play music, listen by looking at watch/zoomed graph and sing several times you will soon get the tempo to sing along with music.

In short, Play music, look at the watch/zoomed graph and try to adjust your vocal speed with the music. It will help you to start vocal along with music and end with music.
Other best way is to print out zoomed music what I have talked in the beginning and take a colorful marker or high light and mark your vocals under music. Vocal marks are where you will sing when music will be playing.

Using headphone, watch and zoom is the easy way to practice.
I know there are some professional methods but this is how we did our practice in shortest way.

Thank you
nihon94