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1) Extremely conservative. Only what is scriptural is allowed. If scripture doesn't mention it or command it, it isn't allowed.

2) Extremely liberal. Anything not forebidden may be allowed. We see this in many churches today.

3) The Via Media. Tradition allows for some practices not mentioned. Every tradition must be checked by scripture and not be against Holy Writ.

I have always heard there is regulative (like your conservative) and normative(similar to your liberal) and liturgical (similar to your Via Media). Churches that are regulative would say to worship God only as He has commanded, but differ among themselves concerning what the Bible says we should do. They are almost always conservative. Normative would say worship that is not forbidden is acceptable, but most restrain it in one way or another and are actually regulative (sort of) by some other standard than Scripture. In fact, I believe there are 'conservatives' and 'liberals' in this group. They usually put their own spin on what is allowed or not allowed. I don't know of a church that doesn't have any restraints, even if they are unspoken and unwritten. My former church had special singing, and even women speaking, but they would have freaked out if dancers came and performed.

Liturgical worship is kind of an expanded regulative that uses both tradition and Scripture as measures for what is allowed.

This is what I've understood since going to a regulative church. When I was going to a normative church, nobody even asked why we did things the way we did.