Global observations: avoid time/duration

Is there any way I could add an observation without the fields time and duration, such that it becomes a track-level observation (e.g., track-level tag)?

[bmcfee]

I agree it’s cumbersome, but time/duration are baked into the definition of an observation:

Yes, the schema is written such that all observations have a time and duration (non-negative float) to validate properly.

I think the correct thing to do here is as @justinsalamon says: make the implicit quantities explicit by documenting the length of the track in the observation fields. Of course, nobody forces you to use that information, but it needs to be there to validate in the schema.

[justinsalamon]

I agree it’s cumbersome, but time/duration are baked into the definition of an observation: https://github.com/marl/jams/blob/255a5ee860b03cec8f889c9986e734a6393a0dbc/jams/core.py#L597-L599 I may be wrong but I believe that supporting observations both with and without time/duration would require a major overhaul that would impact a significant number of lines (apart from the core structure, think validation and every operation currently supported on annotations), if it’s even feasible under the current design.

Since @bmcfee was the main architect behind the observation tuple, he should probably chime in here.