The easiest way to identify which major key it is is to look at the score. At the beginning of the score, there are some sharp and flat symbols behind the treble clef or bass clef. Through these symbols, we know when playing this score. Those sounds need to rise, and those sounds need to fall.

Let’s talk about sharps first, from one to multiple, representing FA, DO, SO, RAI, LA, MI, XI major respectively.

And flats, from one To multiple, they represent XI, MI, LA, RAI, SO, DO, FA major

For example, if there are three sharp signs (#), they represent SO major; For example, if there is a flat (b), it represents XI major.

With the deepening of study, you will have a deeper meaning and understanding of these.

I wish you a happy learning piano!