Notesets
A root and a set of intervals — the fundamental abstraction in NoSheet
A noteset is any interval, chord, or scale described by a root and a set of distances from it. This is the core abstraction in NoSheet: every game runs on a noteset, which relates to other notesets through the intervals it selects and can be transposed to any root.
A noteset also fixes a set of pitch classes. The C major triad, for instance, uses only C, E, and G in any octave — notes you can play as melody or harmony.
The curriculum's notesets nest inside one another: root & 5th ⊂ triad ⊂ pentatonic ⊂ major mode. Each step adds one or two notes to the last.