Theory in spare minutes: where to start

You do not need an instrument, or a long session, to learn theory. A few spare minutes and one clear question are enough.

Start with these three

Intervals. The distance between two notes. Knowing that C to G is a perfect fifth, and why, makes scales, chords and ear training click into place.

Key signatures. How many sharps or flats a key has, and which. Once the order is automatic, reading music gets much faster.

Spelling chords. Name the notes of a chord, in order, from the root. C major is C, E, G. D minor seventh is D, F, A, C. Say them out loud.

How to practise

One question at a time. Answer it, check the answer, and move on. Mistakes are the useful part: note which topic they came from and return to it tomorrow.

Short, frequent rounds beat one long one. Five questions on the bus count.

Where this fits

Better Musician has a Tune-up section for exactly this: ten questions at a level you choose, with an explanation after each one and a record of which topics need more work. No instrument needed.