Determine how many keys of C exist on your keyboard. Keyboards come in different sizes. The most popular sizes come in 88, 76, and 61 keys. If you examine the layout of a keyword, you will notice that it is organized into groups of 2 and 3 black keys with white keys mixed in. The key of C is the first white key which immediately precedes the first black key in the section with only 2 black keys. The one exception to this rule is on shorter keyboards where you will find the key of C as a lone white key immediately after the section with 3 black keys. In this section, the white key after the last black key is the key of B followed by the key of C.
Step2
After determining the number of keys of C on your keyboard, divide this number by 2 and round the result to the next highest integer. For example, if your keyboard has 88 keys with 7 keys of C, divide this number by 2 and you'll arrive at 3.5. Round this number to the next highest integer and you'll arrive at 4. So, the 4th key of C is middle C. Using the same formula, a keyboard with 76 keys has 6 keys of C, so middle C is the 3rd C. Similarly, a keyboard with 61 keys has 6 keys of C, so middle C is the 3rd C.
Step3
If you've successfully located a key of C and aren't sure if you've located another, play them individually. The sounds will be similar except 1 will be 1 octave higher than the other. Also, if both keys are not keys of C, the sound will be dissonant or off.
Novice 
