Hear it before you play it.

A cadence establishes the key, then a note plays - name the scale degree you hear and listen to it resolve home. One rep is one degree named and checked.

A scale plays ascending, root to root - name what you heard. Starts at major vs. minor in a fixed key, works up through any key, harmonic/melodic minor, and all seven modes.

A chord plays - name its quality. One rep is one chord identified and checked, starting at major vs. minor, working up through 7th and suspended chords.

Two notes play - name the distance between them. One rep is one interval named and checked, starting at five common intervals, working up through all twelve, harmonic and melodic.

A short chord progression plays - name its pattern. One rep is one progression named and checked, starting at the two most common pop progressions, working up to minor-key patterns.

A short melody plays - play it back on the on-screen keyboard, note for note. One rep is one melody transcribed and checked, starting at 3 notes, working up to 6 across the full range.

Predict where a tension chord resolves, or hear a progression and name its hidden chord. One rep is one answer checked, starting at V7 to I, working up to secondary dominants and deceptive cadences.

A note plays in tune, then again a little sharp or flat - set the slider to how far off you think it is. One rep is one guess scored in cents, from big 50-cent drifts down to hairline 3-cent ones.