As humans, we have the natural ability to analyse music and we can usually feel music emotionally and sometimes physically. Music can be subdivided into time intervals and this is very helpful when we are DJ’ing. Using simple maths, we can map out entire songs in order to make the next song drop in at the correct time.Most popular songs are 4/4 signature, meaning that there are 4 beats per bar. This is counted as:
1,2,3,4, 2,2,3,4, 3,2,3,4, 4,2,3,4...
This is useful because by knowing how many bars are in the outro of song A, we can correlate that with the intro of song B to drop into the chorus as soon as song A finishes. Knowing your music is a massive advantage as a DJ and is essential for smooth mixing.
As a call to action, you need to start counting all music you hear. It will be hard initially to recognize a one from a two but a good place to start is that the bass or kick drum will usually indicate a one and a snare sound will indicate a two.
Its also worth noting that there are different time signatures, but for DJ'ing purposes 4/4 is the most common.