Sounds

A Sound is a sound event, a category, a volume, and a pitch. Minestom's SoundEvent implements Adventure's Sound.Type, so the vanilla constants can be passed directly:

Sound sound = Sound.sound(
        SoundEvent.ENTITY_PLAYER_LEVELUP,
        Sound.Source.PLAYER,
        1.0F,  // volume
        1.0F   // pitch
);

audience.playSound(sound);

Volume above 1.0F does not increase loudness, only the distance at which the sound is audible. Pitch ranges from 0.5F to 2.0F.

Sources

Each Sound.Source has its own volume slider in the client's sound options, and MASTER scales all of the others.

Source	Vanilla sounds routed through it
MASTER	Nothing directly; its slider scales every category
PLAYER	Damage, leveling up, eating, and other player acts
HOSTILE	Hostile mobs
NEUTRAL	Passive and neutral mobs, including villagers
BLOCK	Block placement, breaking, and block interactions
AMBIENT	Cave ambience and other environmental sounds
WEATHER	Rain and thunder
MUSIC	Background music
RECORD	Jukeboxes and note blocks
UI	Menu and interface sounds such as button clicks
VOICE	The narrator; no world sounds use it

Sound position

playSound(Sound) plays at the audience's own position. The other overloads set a fixed position or attach the sound to an entity:

player.playSound(sound);                              // at the player
player.playSound(sound, new Vec(0, 64, 0));           // at a fixed point
player.playSound(sound, 0.0, 64.0, 0.0);              // the same, as coordinates
player.playSound(sound, Sound.Emitter.self());        // attached to the player
player.playSound(sound, someEntity);                  // attached to another entity

An attached sound moves with the entity. Only Entity and Sound.Emitter.self() are accepted as emitters; any other implementation throws.

Instance#playSoundExcept plays a sound to everyone in the instance except one player.

Stopping sounds

SoundStop selects which sounds to stop.

audience.stopSound(SoundStop.named(SoundEvent.MUSIC_DISC_CAT));  // one sound
audience.stopSound(SoundStop.source(Sound.Source.MUSIC));        // a whole category
audience.stopSound(SoundStop.all());                             // everything

Resource pack sounds

SoundEvent.of creates a sound event for a sound defined in a resource pack:

SoundEvent custom = SoundEvent.of("minestom:ambient.cave_wind", 16.0F);
audience.playSound(Sound.sound(custom, Sound.Source.AMBIENT, 1.0F, 1.0F));

The second argument is a fixed broadcast range in blocks. A vanilla server uses it to decide which players receive the sound; Minestom only serializes the field and does no such filtering, and the client ignores it when computing attenuation. Audible distance comes from the pack's attenuation_distance instead.

WARNING

The key must match an entry in the pack's sounds.json. A client without the pack plays nothing, logging a line to its own log and showing the player no error.