Musical Form and Phrase Structures  

Asymmetrical - A period in which the phrases differ in length 

Symmetrical - A period in which the phrases are the same length. 

Parallel - A period in which the musical material is almost exactly the same. 

Contrasting - A period in which the phrases have differing music material.

Modulation - A period in which the Consequent phrase modulates.

Cadential extension - The addition of musical material beyond the point at which a cadence is expected.

Elision - The cadence point of one phrase becomes the beginning of the next phrase. 

Interpolation - The repetition of a phrase becomes longer by the insertion of new material not heard in the original phrase. 

Phase group - It isn't a period structure, but groups of phrases that end with weak cadences H.C or I.A.C. 

Cadential Phase Group - Group of phrases the dominantly end with P.A.C.

Phrase - A musical sentence or complete thought that ends with a cadence.

Period -A logical grouping of phrases that give an impression of closure. 

Secondary Dominants

Refers to a dominant triad or seventh chord that is the dominant of a diatonic chord other than the tonic. For instance, if we want to figure out the secondary dominant of the target chord A minor, (lets say that the tonic chord is C major) the dominant of A minor is E. Therefore, the dominant chord would be an E7.