John Calvin offers a prolific commentary on freedom in worship:
God did not will in outward discipline and ceremonies to prescribe in detail what we ought to do (because he foresaw that this depended on the state of the times, and he did not deem one form suitable for all ages).... Because he has taught nothing specifically, and because these things are not necessary to salvation, and for the upbuilding of the church ought to be variously accommodated to the customs of each nation and age, it will be fitting (as the advantage of the church will require) to change and abrogate traditional practices and to establish new ones. Indeed, I admit that we ought not to change into innovation rashly, suddenly, for insufficient cause. But love will best judge what may hurt or edify; and if we let love be our guide, all will be safe (quoted in John Piper's Let the Nations Be Glad!).