I know the situation has changed so this is no longer needed but just to make a point. Even if you had another bass tuned to drop D, I think I could tune my E to D quicker than, muting, unplugging, taking that bass off, putting it in a stand, picking up the other bass, throwing the strap over my head, plugging in and unmuting.
I would also tell whoever counts off that song to look at me first and get a nod before counting it off.
I would also tell whoever counts off that song to look at me first and get a nod before counting it off.