Topmusicanswers
C (and its relative minor, A) are the most common by far. After that there is a general trend favoring key signatures with less sharps and flats but this is not universal. E♭ with three flats, for instance, is slightly (though not statistically significantly) more common than F with only one flat.
What is the least common key signature?
A-sharp minor is likely the least used minor key in music as it is not generally considered a practical key for composition. The enharmonic equivalent B-flat minor, which only contains five flats as opposed to A-sharp minor's seven sharps, is preferable to use.
What is the most common key used?
The number one most popular is... the space bar. Another fun fact from Goud: 90% of people only use nine fingers when typing — they don't use their left thumb, because they use their right thumb to hammer the space bar. Microsoft built a keyboard with a split space bar.
Why is G major so common?
You can hear music that starts in G major all over the place: it's one of the most popular keys to compose in. That's because it works well in the circle of fifths theory, with many of the notes being core components of other keys [2].
