Tonal Organization of the first section

 

 NOTES

FORM

OPEN

or

Continuous

ABA ends in a related key
B returns to the tonic		Binary
A Bsecond section is often at first only loosely thematically related to the firstSimple Binary

AA'

 The dominant ending of A is repeated in the tonic at the end of A'

Balanced Binary

|:A:||:B A’:|

  • B is a sequential interlude

  • B is open

  • B is based on motivic material from A

Rounded Binary

If A’ is the same length as A Kostka calls it Ternary

|:A:||:B A’:|

  • B is a closed section

  • B is substantial

Incipient Ternary

Rounded Binary

Asymmetrical Rounded Binary

|:A:||:B ½A’:|

  • B can be anything –

  • There is only half of A (Kostka)

Rounded Binary

 

 

 

CLOSED

or

Sectional

AB

  • There is usually a 'pause" in the middle of B

  • There is a half cadence in B

Binary

ABA

  • Each section is closed

Ternary

AA’ B AA’

(da capo aria)

 

Ternary

|:A:||:B A:|

  • B is a sequential interlude

  • B is very short

  • B is based on motivic material from A

Rounded Binary

Asymmetrical Rounded Binary or Incipient Ternary

|:A:||:B A:|

  • B is a substantial contrasting Section

Ternary

 Closed

A B A

  • Each section is a form itself

  • Minuet and Trio

Compound Ternary

  • A section is labeled closed when it ends with an authentic cadence in the original key
  • An section is open ends with either a half cadence or a modulation to a new key area.