Here are other places for #participatory #openscores! Each with a flavor!

#journals:
Synzine - #games! access through #wiki links seems easiest:
http://musicgames.wikidot.com/wiki:synzine-magazine

Improvised Music - Open Scores - also with essays - appears regularly, we'll toot about new issues.
http://im-os.net/

#websites
#GreatLearningOrchestra's "short" tunes:
http://a4-room.com/

#BillDrummond's project:
http://the17.org/

Closer to "theater" with occasional music:
https://1000scores.com/