Opening movement
The first movement of a cycle.
What it means
The opening movement (German Kopfsatz) is the first movement of a multi-movement work — a symphony, sonata, concerto, or string quartet. In the classical layout it carries the greatest formal weight and usually stands in sonata form with exposition, development, and recapitulation, often with a slow introduction before it and a coda at the end. It fixes the key and character of the whole work.
Musical use
The significance of the opening movement is connected with sonata form: there two or more theme areas are presented in different keys, worked out in the development, and led back to a common key in the recapitulation. This process is the formally most complex in the whole work and establishes the precedence of the first movement over the following ones. In the nineteenth century the weight partly shifts toward the finale, which then becomes the goal of the whole. In older cycles such as the Baroque suite there is no such distinguished first movement.
Performance practice
First get a formal overview and mark exposition, development, and recapitulation; without this orientation the movement seems arbitrary. Do not shape the recapitulation as a mere repetition but observe the changed key relations. Keep the basic tempo in view over the whole movement, even with contrasting themes. Note repeat signs and decide deliberately about their execution. Plan your strength so that development and coda still allow for intensification.
Bear in mind that the repeat of the exposition is prescribed in many works and has a formal function: it makes the theme areas familiar before the development works them out. Decide deliberately and with reasons if you omit it. Mark the formal sections and observe the changed key relations in the recapitulation. Check whether the exposition is to be repeated, and include the decision in the overall planning of the duration.
Check whether a slow introduction precedes it, and plan its relation to the main part deliberately.
Also check whether the coda introduces material of its own, because it is then more than an appendix and demands shaping of its own.