The 4/2 time signature is a time signature that is found in our Rookie-level lessons. When creating our Rookie content, we decided to use this time signature for two reasons:
1. Since one's level of confidence is very important when attempting to learn how to play the piano for the first time, we wanted to create an environment where our users could look at the sheet music in our lessons and not feel intimidated. To accomplish this, we augmented all of our music, making the quarter note the shortest duration, therefore removing all beams and flags. This approach makes the music look less scary and more approachable.
2. Because the 4-count is so important in music, we wanted to instill the 4-count into our users' minds early and often. Rather than writing our music in 2/2, instead we wrote it as 4/2. This allows us to use the half note as the beat (making the quarter note the + of the beat) and still count 4 beats before starting our count back at 1.