Strengthening Endings with Strong Predominants

Not all predominants are equally powerful. A plain IV chord (or its close relative ii in root position) provides adequate harmonic support, but two chords consistently generate more momentum toward the cadential dominant: ii⁶ (supertonic triad in first inversion) and IV⁶ (subdominant in first inversion). ii⁶ places 4̂ (fa) in the bass, while IV⁶ places 6̂ (la); in both cases the bass approaches the dominant's 5̂ smoothly by step rather than by leap, setting up the dominant with more energy than root-position IV.

Of these, ii⁶ is particularly effective. Its bass note (4̂) rises by step to 5̂ under the dominant, and its upper voices contain the same pitches found in IV, so it smoothly prepares V or V⁷. The chord avoids the parallel fifths that can arise when root-position IV moves to root-position V, making ii⁶ the preferred predominant in strict voice-leading contexts. Composers from Bach through Beethoven reached for ii⁶ whenever they wanted a phrase ending to feel inevitable.

IV⁶ is a similarly strong option: its bass note is 6̂ (la), the third of IV, which descends by step to 5̂ (sol) under the dominant — a smooth, singing approach to the cadential arrival. The upper voices of IV⁶ share pitches with ii in root position, so the two chords are nearly interchangeable in sound while differing in bass voice-leading. Both ii⁶ and IV⁶ are called "strong" predominants precisely because their bass notes approach 5̂ by step rather than by leap, tightening the harmonic drive toward the final cadence.