One thing that you should take note of is that not all songs are written based upon concert pitch. Concert pitch also means songs are written in the key of C major, which contains all and only the white notes on the piano. If all music were written in this key, the world would be an extremely boring place. Hence, most music are written in various keys either for variety purposes or to complement the vocalist’s singing range.
You would have to bear in mind that if a song is written in a different key, then some of the notes in the scale will always be played as either a sharp or a flat. This is also where those black keys on the piano come into play. In such cases, the first bar of the song will contain the key signature in which either sharps (represented by the symbol 
) will be placed on the notes to be played as the note to the right of the regular white notes, or flats (represented by the symbol 
) will be placed on the appropriate lines to indicate which notes should be played as the note to the left of the regular white note. This note will then be played as either a sharp or flat note indicated unless otherwise stated beside the note in a later bar of music. However, as soon as that bar ends, it will return to being what the key signature specified. In fact, there are only 15 possible key signatures and 3 of them are just duplicate methods of notating the same key, so in reality there are only 12 possible keys to play in.
In music pieces with key signatures, the notes stated to be played sharp or flat would be played as sharp or flat for the entire piece unless they were cancelled out by a natural sign (
). If a natural sign is encountered in front of a note, then all notes with the same name as that note within that bar would be played as the “natural” white piano notes instead of the sharp or flat ones. However, the notes in the next bar afterwards would be played the way the key signature specifies.
Then, there are also some musical pieces that may have different sections written in different keys. They will begin with a certain key signature indicating what key to play in. As the song progresses, another key signature may come into play. This indicates that from that point on, you will have to play the notes the way that key signature specifies until possibly another key signature is encountered.
If you are looking for quality piano lessons in Singapore, a certified teacher should be your main priority. At Awesome Piano, we have a pool of qualified piano teachers to assist in our students’ learning.