How do you work out the time signature on a piece of music?

The easiest way to do this is to listen to the piece, lightly tapping your finger to the beat...

Now the harder part is to find where the strong beat falls and to decide whether this is in Simple or in Compound time. try counting along with your tapping and feel the strong beat.

If you are feeling 1 2 1 2 1 2 1 2 it is in 2/4 Simple Duple Time
If you are feeling 1+a 2+a 1+a 2+a it is in 6/8 Compound Duple Time

1 2 3 1 2 3 it is in 3/4 Simple Triple Time
1+a 2+a 3+a it is in 9/8 Compound Triple Time


1 2 3 4 1 2 3 4 it is in 4/4 (common time) Simple Quadruple Time
1+a 2+a 3+a 4+a it is in 12/8 Compound Quadruple Time

Duple time will often feel quicker and lighter than 4 / 4
Triple time will feel 'waltz like'
Quadruple Time will feel march like