Fraction = a number describing parts of whole.  The numerator is the top number, 
                  and the denominator is the bottom number.

Example - 4/2 indicates that there are to be 4 beats in a measure, each one being held for two counts.

Pitch is how high or low a note sounds.  A notes pitch is given by the frequency of its vibration. 

Frequency = the number of times a pitch occurs

Rate = a comparison of two numbers with different units

Unit Rate = rate with denominator of only 1 unit, found by dividing the numerator
                 and denominator by the same number that causes the denominator to 
                 be 1.

Example - 20 cycles
               10 seconds
               The frequency (rate) is 20 cycles/10 seconds, read as 20 cycles per 10 
               seconds.
               The unit rate is 2 cycles per second.  (Divide numerator and denominator by 10.)

The difference in pitch between two tones is called the interval.  Intervals are expressed as ratios of the frequencies of the two pitches.

Ratio = a comparison of two amounts with the same units.  Ratios must be read 
             in the order of the amounts

Example - Note A has a frequency of 2
                Note B has a frequency of 1
               The ratio of A to B is 2:1, 2/1, or 2 to 1 (all read as 2 to 1).
               The ratio of B to A is 1to 2.

The rhythm of music is the multiple of its measures. 

Multiple = multiplication product of a number and any whole number

Example - The first five multiples of 2 are 2*1=2, 2*2=4, 2*3=6, 2*4=8, and 2*5=10.
 

For more math, visit these sites:
http://www.math.com
http://coolmath4kids.com