It is very important to know the timing of the song to synchronize with the animating visuals. For that I used technique called ‘sound scrubbing’.
Sound scrubbing can be done using editing software. If you don’t have any software right that time, you can use stopwatch and can mark the timing.
I scrubbed the song using software called toon-boom as I am planning to do animation in the same. While scrubbing I calculated the time required for each sentence and stanza to complete. Then marked the frames required for each stanza and chorus. Also, I marked the vocal and instrumental parts of the songs.