Dominant seventh chords are diatonic seven chords of the fifth scale degree or V 7 chords. Has a distinct sound from the tritone that forms between the third and seventh of the chord. Most commonly resolves to the I chord.

Renaissance – frequent dissonant sonorities suggest beginnings of seventh chord use. Baroque – Composers introduce functional harmony in general. While this includes dominant seventh chords the are used sparsely at first and eventually become more popular. Classical – Plentiful use of dominant seventh chords. Romantic – Very bountiful use dominant sevenths.

Leading tone seventh chords are half and fully diminished seventh chords on the seventh scale degree vii 7 vii 7. These are closely related to the Dominant Seventh chords because they contain 3 of the same tones. Generally resolves to the I chord.

Renaissance – Not used Baroque – Sparsely used yet included in harmonic vocabulary. Classical – Similar uses as in the Baroque era. Romantic – Freer use of leading-tone sevenths

Any diatonic seventh chords that that don’t possess dominant function.

Renaissance – Generally not used Baroque – Sparsely used at first but grow in popularity. Classical – Similar uses as in the Baroque era. Grow in popularity and are used a lot. Romantic – Become less common.

V 7 vii 7 I 7 ii 7 ii 7 iii 7 III 7 IV 7 iv 7 vi 7 VI 7 (Contain Tritones)(Doesn’t Contain Tritones)