…of four albums I have sheet music versions of.
For non-musicians, pretty much all (well, Western) sheet music is written in a particular “key”–basically the set of notes that you’ll most likely be using in a song. All things being equal (and all things are never equal), the fewer “accidentals” piano music has, the easier it is to play–so zero accidentals are relatively easiest, one and two are decent, three and four are getting trickier, and nobody wants to deal with five or six.
This is a graph of four sets of piano songs, from beginning to end. Songs that change keys in the middle of the piece are marked accordingly, but this is not to scale at all–if I show a key change halfway through a piece, it might not actually be halfway–it’s just that the song’s in two different keys.
There are a couple spots when the graph goes horizontal in the middle of a song. That’s because there was a change from (say) one flat to one sharp (they’re equally difficult on average, but it’s still a change worth marking).
Yes, the fourth songs in each of these books all begin with four accidentals.
Click once or twice for larger size, I uploaded a big version.