Why it pays to know what is inside

Most players meet their Anglo from the outside: the bellows in the lap, the buttons under the fingers, the straps snug across the back of the hands. That is where the music happens, but it is not where the character comes from. The reason one C/G feels free and singing while another of the same make feels stiff and shouty is hidden under the ends: the reed pan, the chambers cut around each reed, and the little action that lifts a pad off its hole when you press a button.

Take the six screws out of one end on a quiet afternoon and you will learn more about your own playing than a month of scales. Nothing inside is fragile if you are careful, and everything inside explains something you have probably felt but never quite named.

The reed pan and its chambers

The reed pan is a wooden plate, usually the same timber as the body, with slots cut clean through it. A reed shoe sits in each slot, held with wax or occasionally with a dovetail fit. Around every slot a walled chamber is built up, so each reed lives in its own small room. That room is not decoration: it is part of the instrument's voice.

Chamber volume is matched to the pitch of the reed. A low G wants a deep, generous chamber, which gives it weight and body. A high D wants something small, so the reed can start instantly and speak cleanly. Get it wrong and you hear it at once: a chamber too small for its reed chokes and refuses to sound at low pressure, while one that is too large makes the note slow to start and woolly in the low register.

• Chamber walls must be airtight to each other. Leakage between neighbours makes a note breathy and unsteady, and wastes air you needed for the bellows.
• The opening of each chamber lines up with a hole in the action board, closed by a felt-padded pad. Pad and chamber together are the reed's front door.
• Pan thickness matters as much as chamber depth, especially in the middle of the range where most of your tunes live.

Reeds, tongues and the feel of the response

A reed is a metal tongue fixed over a slot in a brass or zinc shoe. Steel is standard in anything modern or well restored, and gives a bright, stable note. Brass tongues are older and softer, warmer and sweeter, though easier to knock out of tune.

Reeds come in long-scale and short-scale patterns. Long-scale reeds give a fuller, more flexible tone and respond well to changes of bellows pressure, but they take more air. Short-scale reeds speak faster and cut through a session, at the cost of a thinner sound. This is one reason two Anglos with identical fingering can feel so different under the hands.

The gap between the tongue tip and the shoe — the set — is the biggest single influence on response. A wider gap needs more pressure but is stable and loud; a closer gap speaks fast but can buzz or choke. Rust on a tongue will never behave consistently, and no amount of reed bending will cure it.

The action: button, lever, pad

Press a button and a lever pivots on a post, lifting a pad away from a hole. That is the whole mechanism, and its geometry governs how quick the instrument feels. Button travel should be short and crisp. If a button feels spongy, or the pad bounces as it closes, you lose speed exactly where fast dance tunes need it.

• Pads must sit flat on their holes. Even a small leak drains the bellows and blunts the response of every other note.
• Springs should be light enough for quick repeated notes, and strong enough to seat the pad firmly every time.
• Felt washers and bushings keep buttons quiet and centred; worn ones let buttons rattle and tilt.

Why the same tune feels different in another key

Because reeds and chambers are laid out in rows, each row of buttons draws on a different set of rooms. On a C/G Anglo, the G row sits lower and asks for more air per note than the C row above it. Play a tune in the home keys and it feels relaxed; push the same tune into a key that forces you onto the other row, or across both, and the bellows start to complain.

This is what cross-row playing is really about. Choosing a fingering that alternates between rows does not just ease awkward notes, it keeps the air demand steady, so the bellows stay quiet and even. Players who own both a C/G and a G/D often discover that a tune they fought on one instrument sits beautifully on the other, purely because the chambers suit the register better.

Keeping the insides healthy

Store the instrument in its case, away from radiators and damp, and keep dust out of it. Valve leathers harden and curl with age and cause a buzzing or gasping note; wax cracks and lets a shoe come loose, which buzzes in sympathy. Play slowly through every note now and then and listen for one that is weaker, slower or noisier than its neighbours.

Do not oil the action. A dry lubricant at most, never anything wet. If a reed has genuinely gone off pitch, the work is done by careful filing: as a rough rule, metal taken from the tip of a tongue raises the pitch, and metal removed near the base lowers it. It is a job for someone with a tuner, good light and scrap reeds to practise on. The rest — clean pads, flat seating, a snug case — is well within reach of any player willing to take an end off.