How to stay in key

What it sounds like

Individual notes sound fine on their own, but something grinds against the music. It usually starts after a modulation, a key change, or a long instrumental section with nothing to hold on to.

What is actually being measured

Your sung pitch class against the harmony actually sounding underneath it, weighted by how dissonant the clash is and how long it lasts. A brief passing note that disagrees with the chord is not the same event as a held note a semitone away from it, and the measurement does not treat them as one.

A key problem opens above 15 units of weighted clash severity per minute, and counts as severe at 120.

Why it happens

Key drift is a memory problem more than a pitch problem. Without a reference sounding, the ear slowly re-centres on whatever it heard most recently — usually your own last note — and after a few phrases the whole performance has migrated. Modulations and long gaps between vocal entries are where it starts.

How to fix it

• —Learn the chord roots, not just the melody. Singing the root of each chord as it changes is the single most effective exercise for this fault.
• —Re-anchor at every entry. Find the note in the accompaniment before you come in rather than continuing from where you left off.
• —Practise the modulation on its own, slowly, with only piano chords underneath.
• —A cappella takes cannot be scored for key at all — there is no harmony to compare against, so a recording with no backing track has nothing to be out of key with.

The drill

Chord-root matching and interval work against sustained harmony, with the reference always sounding — the point is training the habit of listening down into the chord rather than across from the last note.

Common questions