Mutes

A mute is an object placed in the bell of a brass instrument to alter its timbre. It is not primarily a volume control — it is a color choice. Some mutes can play louder than open horn in their resonant range. Treat mutes as the brass orchestrator's primary palette tool, not a way to turn the brass section down.

The Standard Mutes

Mute	Sound	Common On	Listen
Straight	Nasal, focused, slight edge	Trumpet, trombone, horn, tuba	Stravinsky, Soldier's Tale (trumpet)
Cup	Softer than straight; warmer, less edge	Trumpet, trombone	Big-band brass section pads
Harmon (stem in)	Buzzy, electric, distant	Trumpet	Miles Davis, Kind of Blue
Harmon (stem out)	Hollow, piercing — "wah" potential	Trumpet	Miles Davis, Sketches of Spain
Plunger	Hand-controlled "wah-wah"	Trumpet, trombone	Ellington — Cootie Williams, Tricky Sam Nanton growls
Bucket	Veiled, dark, woolly	Trumpet, trombone	Big-band ballad writing
Hat / Derby	Soft, distant — like "hat over bell"	Trumpet, trombone	Ellington plunger-and-hat alternations

Plus less common: stop mute (horn, very nasal), wah-wah/clear-tone (trumpet, hand-operated), whisper mute (practice tool, occasionally used for ppp).

Notation

con sord. — put the mute in
senza sord. or open — take it out
Specify the mute the first time: (straight mute), (cup), (harmon, stem in). After that, con sord. is enough until the mute changes.
Plunger: mark + (closed) and o (open) above the staff for hand position.
Give time to switch. Mute changes need at least a bar of rest, ideally two — more if the player has to reach into a bag.

Per-Instrument Notes

Trumpet — full mute palette. Standard player carries 4–5 mutes.
Trombone — same palette as trumpet but proportionally larger; bass trombone needs an extra-large straight.
Horn — its own world. Hand stopping (the right hand fully closes the bell) is the original "mute," producing a distinctive nasal cuivré sound. Stop mute approximates this. Notate + for stopped, o for open. Modern horns have a stop valve to keep the pitch in tune; older horns shift sharp by a half-step when stopped.
Tuba — straight and cup mutes exist but are rarely used. Most tuba mute writing is novelty.

When to Use a Mute

Color shift in a quiet passage — dark cup mute on trombone for a sustained inner voice
Distance / cinematic — bucket mute trumpet for "from another room"
Vocal/jazz expression — plunger trumpet/trombone for the entire history of swing
Cuivré (brassy distortion) — the horn's "stopped fortissimo" for moments of menace (Mahler 1, last movement)

Watch — Mute Demonstrations

Demonstration of 10 Different Trumpet Mutes

A/B comparison of every standard mute on trumpet — straight, cup, harmon (stem in/out), plunger, bucket, practice mutes. Hear before you write.

Brass Mutes Demonstration (trumpet + trombone, 7 mutes)

The same mute on different instruments so you can hear how it scales across the section.

Listen — Mutes in the Repertoire

Miles Davis — So What (Kind of Blue, harmon mute)

The canonical harmon-mute trumpet sound. Stem-in throughout. Probably the most copied muted-trumpet recording in history.

How to Play Harmon Mute Trumpet Like Miles Davis

Tutorial on what makes Miles's harmon-mute tone distinctive — air column, embouchure, mute placement. Useful for understanding why a mute is a color choice, not just a volume control.