Secondary leading-tone seventh chord substitutions

vii^°7/IV or

vii Ø⁷/IV

IV [1]

vii^°7/iii

vii^°7/vi

vii^°7/ii

vii^°7/V or

vii Ø⁷/V

vii^°7

or

 vii Ø⁷

I

Secondary leading-tone triads substitutions

vii^°/IV

IV [2]

vii^°/iii

vii^°/vi

vii^°/ii

vii^°/V

vii^°

I

Secondary Dominant seventh  substitutions

V⁷/IV

IV[3]

V⁷/iii

V⁷/vi

V⁷/ii

V⁷/V

V⁷

I

Secondary Dominant triad substitutions

V/IV

IV[4]

V/iii

V/vi

V/ii

V/V

V

I

Circle of fifths

I

IV

viiº

iii

vi

ii

V

I