Semitones and whole tones
The distance between adjacent piano keys, with no key in between, is a semitone. C to C♯ is one semitone; C to D is two semitones, or a whole tone. E–F and B–C have no black key between them and are also semitone steps.
An interval is a distance between notes
C–D is a second, C–E a third and C–G a fifth. Letter names determine the interval number; semitone counts help determine its quality. C–E spans four semitones and is a major third. C–E♭ spans three and is a minor third.
Major and minor triads
C major contains C–E–G: a major third followed by a minor third, or 4 + 3 semitones. C minor contains C–E♭–G, or 3 + 4 semitones. Listen to how changing just the middle note changes the colour of the chord.
Chord inversions
Arrange C–E–G as E–G–C or G–C–E and the notes still form C major. These are inversions. A different arrangement can move your hand closer to the next chord and make the movement of individual voices smoother.
Pulse and rhythm are different
Pulse is the steady underlying beat. Rhythm is the pattern of notes and silences within it. Count four beats and play one sound on each beat. Then divide one beat into two equal sounds while maintaining the same underlying pulse.
Find the idea in a composition
Watch where the bass changes and which melody notes feel like points of rest. A repeated chord or interval becomes a recognisable idea rather than an isolated key press. Start by hearing one concept clearly instead of trying to label every note at once.