30 topics
Music theory help, from intervals to four-part writing
The point where music theory stops being obvious is usually roman numerals: the same C major triad is I in one key and V in another, and nothing printed on the page tells you which. Analysis turns out to be a running argument about what a chord is doing, not a labelling exercise — and part-writing marks go the same way, lost to rules that were memorised without the reason they exist.
Where students get stuck
The same chord gets a different roman numeral every time
Because the numeral names a relationship, not a chord. A C major triad is I in C major, IV in G major, V in F major and VI in E minor, and it behaves differently in each: as I it is home, as V it is under pressure to fall to its tonic. So the first thing written on any analysis is the key, and the numeral is just the scale degree its root sits on. Case carries the quality — uppercase for major, lowercase for minor, a small circle added for diminished — which is why vii° in a major key is always the diminished triad on the seventh degree, and why a numeral written without regard to case is only half an answer.
There is an accidental in the bar and the chord is not in the key
In tonal repertoire that is usually a secondary dominant, and the accidental is the tell. Take the chord and ask which key it would be the dominant of, then look at whether that key's tonic is the very next chord. In C major, a D–F♯–A triad is not ii, because ii is minor; D major is the dominant of G, and G is V in C, so it is labelled V/V and it resolves to G. The raised note exists to create a temporary leading tone — F♯ pulls up to G the way B pulls to C — which is also why you spell it F♯ and never G♭. The accidental is doing a job, and naming the job is the analysis.
I lost marks for parallel fifths and I cannot hear anything wrong
You are not meant to hear a wrong note. You are meant to hear four voices briefly become three. When two parts move in the same direction from one perfect fifth to another, or one octave to another, they fuse acoustically and stop sounding like independent lines — and independence of line is the whole premise of the style being marked. The check is mechanical: take the voices in pairs, soprano with alto, soprano with tenor, soprano with bass and so on down, and look at each pair across consecutive chords. Writing the outer voices in contrary motion where you can removes most of them before you ever check.
Naming intervals takes me forever and I still get the quality wrong
Do it in two passes. Count letter names inclusively first: C up to G touches C, D, E, F, G, so it is a fifth of some kind before any accidental is considered. Then fix the quality by half steps — a perfect fifth is seven. Inversion gives you the rest free, because an interval and its inversion always add to nine and the quality flips: major becomes minor, augmented becomes diminished, and perfect stays perfect. So knowing C–E is a major third tells you E–C is a minor sixth without counting again. It is also why spelling matters: C–F♯ is an augmented fourth and C–G♭ a diminished fifth, identical on a keyboard, and they resolve in opposite directions.
What's covered
Music Theory topics you can work through with a tutor, generate practice on, or turn into flashcards and a study plan.
Notation and rudiments
- Treble, bass, alto and tenor clefs
- Note and rest values, dots and ties
- Simple and compound time signatures
- Key signatures and the circle of fifths
- Accidentals and enharmonic spelling
- Dynamics, articulation and tempo markings
Scales and intervals
- Major scales and the three forms of minor
- Relative and parallel keys
- The modes
- Pentatonic, blues and chromatic scales
- Interval size, quality and inversion
- Consonance, dissonance and the tritone
Chords and harmony
- Triads, qualities and inversions
- Seventh chords and their inversions
- Figured bass and roman numeral analysis
- Cadences: authentic, plagal, half and deceptive
- Secondary dominants and tonicisation
- Modulation to closely related keys
- Non-chord tones: passing, neighbour, suspension, anticipation
Voice leading and counterpoint
- SATB ranges, spacing and doubling
- Parallel and hidden fifths and octaves
- Resolving the leading tone and the seventh
- Harmonising a given bass or melody
- Four-part chorale writing
- First and second species counterpoint
Form, rhythm and aural skills
- Phrase, period and sentence structure
- Binary, ternary, rondo and sonata form
- Rhythmic and melodic dictation method
- Sight-singing and solfège
- Score reading and transposing instruments
Music Theory questions
Does this cover RCM theory exams, AP Music Theory, or a first-year university course?
The written ground is shared across all three, and the topic list above spans it. What differs is emphasis and vocabulary: the RCM levels move from rudiments up through harmony and analysis in fixed steps, AP weights roman numeral analysis and part-writing heavily, and a university course adds species counterpoint and more chromatic harmony. Name yours and it uses that terminology.
Can it help with ear training and dictation?
Partly, and it is worth being exact about which part. It cannot play you the excerpt — use the recordings your course provides for that. What it can do is teach the method: identifying an interval against a song you already know, notating rhythm by counting subdivisions instead of guessing at note values, and checking the transcription you wrote down against what the harmony makes plausible.
Can it check a four-part harmony exercise I have written?
Yes. Photograph the page or share your screen and it goes chord by chord, naming the beat and the pair of voices where a rule breaks rather than just saying the exercise is wrong. Most part-writing errors are two or three recurring habits, so seeing them located on your own page tends to fix more of them at once than a corrected version would.
Do I need to play an instrument to do well at this?
No. Written theory is a paper subject and the analysis skills are about notation and function, not technique. Playing does help in one specific way — hearing a deceptive cadence land where you expected a tonic makes the label stick — but a keyboard you can pick out chords on is enough for that; you do not need to be able to perform the repertoire you analyse.
Stuck on music theory right now?
Talk it through out loud, share your screen, and watch it worked out step by step on a whiteboard.
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