Remotely and asynchronously.

There are never enough students to make a full concert band at the local community college, so people from the community round out the band.

The conductor's planning on sending a timekeeping video, and everyone is supposed to audio-record their part. Fortunately no one (except maybe a cat or two) will be bothered by tromboning at home (assuming it's not the middle of the night or migraine/etc. season).