…I’m beginning to see a trend here.
Good reed + Good playing day = Good rehearsal.
Good reed + Lousy playing day = Okay/Not-so-good rehearsal.
Bad reed + Lousy playing day = Not-so-good rehearsal.
Bad reed + Bad playing day = Disaster.
Conclusion: Its the darned reed. Argh. ( I’m pretty sure most, if not all, oboists will agree)