I specialise in large-scale group musical interaction – and would love to offer this to the conference as a group energiser, if it fit the programme! Typically this could last 10-15 minutes (can be shorter if need be), and would be an interactive segment that would bring all of the delegates present into a brief creative, musical interactive experience where every member is an active participant. For an example, please see the following video, where this was run with 1200 people: https://youtu.be/MQo-1qlKUBE?t=271
This could be run alone, or with support from an impromptu percussion band pulled together from other delegates (which has staging/amplification implications), or one that has been developed in a separate workshop prior to the slot. It’s relatively simple for me to bring instruments for up to 100 people to play, and I’m happy to explore sources of support to access a greater number of instruments if need be. Alternatively, it can be run entirely with objects that delegates will have around them. I’m very happy to collaborate on a plan that best fits the goals of the conference!