Very short scores (written instructions for performance) of 280 characters or less.
These scores are inspired by:
A third and only slightly more distant inspiration is Yoko Ono's Grapefruit, a book of Fluxus instruction pieces.
Everyone can make sound. Musicians make intentional choices to make sound. Beginner's mind will suit you fine here.
Expertise is not the aim. Pick any instrument that you can use to make notes aka individual units of sound. Synth software is not ideal. Being able to make responsive intuitive sounds, by hitting a button, by making sound with your mouth, by tapping a drum, pressing piano keys is great. If you use a phone app or device, be able to play individual sounds on command.
Improvised music has natural endings. You must mutually accept them rather than rush past and keep making noise. Endings are often at moments when you would take a breath, when a section feels like the point was just made, when a silence has just happened, or when it just feels right. Accept the ending. Enjoy the feeling of ending a piece.
List of Scores
Choose a sound texture like blowing wind, sigh, hum, etc. Start small and repeat the texture, making variations and leaving space, allowing yourself to breathe between sounds. Don't worry whether it's music. Continue for 1 to 2 minutes. When it feels right, begin to fade out.
One person starts improvising a 30 sec solo, with a beginning, middle, then end with a nod, breath or gesture to bridge to the next player, who immediately begins their own 30 second section. Continue to alternate between players in 30 section chunks. Do at least 3 sets.
Call and Response
Play a short segment of just a few notes or sounds. Your partner plays back a similar sounding pattern. You repeat. Your partner repeats. As you go back and forth, allow yourself to be influenced and drift with your partner as you echo back together.
Dots and Dashes
All players make fast short (aka "staccato") notes rapidly. Gradually, together, begin slowing the speed of your notes, mirroring sounds, til a note stretches out long. One person starts and all begin gradually speeding up till eventually ending with rapid sounds again.
Bobby McFerrin - Circle Songs - voice
Mary Halvorson and Miles Okazaki - Jazz Fest Sarajevo 2020 - guitars
White Noise Sessions - sax, drums
Hanatarash / live in La Mama - drums, barrels
Tom Hall recorded a year of videos dedicated to free improvisation (http)