Editing Binary form (section)

===Balanced binary===
Balanced binary consists of ending the first and second sections with analogous cadential material (and arguably pre-cadential material).  The usual pattern for balanced binary is continuous (''i.e.,'' the first section ends off tonic), with the two sections ending in "rhyming cadences", in which the same cadential material occurs in both sections, appropriately transposed for their keys.  
This differs from Rounded Binary, since in a Rounded Binary form, thematic material from the A section must return at the end of the B section (which usually occurs at the beginnings of phrases), whereas in a balanced binary, it is sufficient for a meaningful portion of the end of the final phrase to return.

For example, if the A section is a ''period'' (using Caplin's naming conventions; elsewhere called a ''parallel period''), the first ("antecedent") phrase of the A section will begin with a ''basic idea'' (generally for one half of the phrase) and end with a relatively weak cadence, and the second ("consequent") phrase will begin with the same ''basic idea'' and end with a stronger cadence; alternatively, if the A section is a ''sentence'', the first half of the section will consist of two repetitions of the ''basic idea'' (with the second possibly transposed or slightly altered), and the rest of the phrase will drive towards a cadence.  In a rounded binary form, at the end of the B section, if the A section was a ''sentence'', typically the beginning of the sentence returns, potentially abridged, followed by the cadence; if a ''period'', the same is true, but since the antecedent and the consequent of a period both begin the same way, it is generally simpler to say that the entire consequent phrase returns.  However, in either case, it is the ''basic idea'' that returns, followed by the cadence.
In a balanced binary, the ''basic idea'' need not return.  There is some room for debate concerning how much material must return preceding the cadence; it is a subjective decision upon which theorists may differ.  Thus, it is not always clear how the concept of balanced binary should apply if the A section is a ''period''.  However, if the A section is a ''sentence'', the balanced binary may bring back the entire second half of the A section (transposed if appropriate) without ever bringing back the ''basic idea''.

There is also some room for debate concerning how the concept of balanced binary should relate to sectional binary forms.  In principle, there is no intrinsic reason why a sectional binary form in which the second half of the A section (whether ''sentence'' or ''period'') returns at the end of the B section should not be considered balanced since they end with the same cadences.  From this point of view, many rounded binary forms are also balanced (especially those in which the A section is a ''period''), but the fact that they would be balanced would be effectively uninteresting because the fact that they are rounded supersedes this characteristic.  However, if one considers rhyming cadences in different keys to be a defining characteristic of balanced binary, then balanced and rounded binaries are mutually exclusive but analogous structures belonging, respectively, to continuous and sectional forms.