A key/scale with the spelling it is conventionally written in beside it.
What the key builders hand back. It is a KeyScale — every reader that
wants only the pitch classes takes it unchanged — and it carries the tonic
those pitch classes are conventionally written on, so it also satisfies the
entry points whose answer depends on how the key is written.
Carrying the spelling here is what lets those entry points refuse a bare
KeyScale without refusing the library's own builders. A bare scale reaching
one of them has had a spelling and lost it, which is the defect; a built key
never lost one.
A key/scale with the spelling it is conventionally written in beside it.
What the key builders hand back. It is a KeyScale — every reader that wants only the pitch classes takes it unchanged — and it carries the tonic those pitch classes are conventionally written on, so it also satisfies the entry points whose answer depends on how the key is written.
Carrying the spelling here is what lets those entry points refuse a bare
KeyScalewithout refusing the library's own builders. A bare scale reaching one of them has had a spelling and lost it, which is the defect; a built key never lost one.