Make a really meaningful sound that lasts a minute max.
If you don’t find it the first time, repeat until you find it. Choose it with care.
Remember it or record it.
Cherish it.
Make continuous sound (include intentional silences) with your body or instrument for at least an hour.
Choose: where you are. how/if you’re moving. what you’re doing.
How long can you sustain this for? Do you need to change something to sustain it for longer? How do you feel after?