[Oberon]

An expedient does not add to a command. Examples would be meeting in a building, using microphones, etc. An addition does just that, it adds to a command. Such is the case of using mechanical instruments in worship.

I understand the distinction that you're trying to draw, but for the life of me I cannot grasp how you mean to apply it to the example you cite. How is it that singing along with an instrument "adds to a command," but singing in a polyester sweater is merely an expedient?

It seems to me that your distinction is an awfully thin one to hang a doctrine on.

[jkl1122]

I will use your example. If I am wearing a polyester sweater and singing praises to God, I am still just singing praises to God. However, if I am playing a mechanical instrument and singing, then I am both singing praises to God, and playing an instrument. Those are two different types of music. There is one specified in the command, and that is singing.