A tonic pedal can be very effective at any point in a piece. Try different chords against it and see how it works out. You can get away with quite a lot of dissonance as long as the dissonant notes resolve by step back to notes that fit with the pedal. In the example from the opening of a Beethoven string quartet below, there are a variety of harmonies some consonant (i in bar 1, iv in bar 3) and some more dissonant (ii at the beginning of bar 5, vii7 in bars 2 and 6).
Beethoven Op. 18 No. 4, first movement
|In terms of diatonic chords, the following fit particularly well over a tonic pedal
In this next example, Mozart uses a tonic pedal as part of a coda before some final perfect cadences. Features to steal include:
- a hint at tonicising the subdominant, so in the second bar we have I with a flattened seventh acting as a dominant seventh to chord IV in the third bar
- use of a nice, dissonant chord vii the fourth bar (resolving to I in the next bar but the D and the Ab are held over as suspensions for another beat)
Mozart Quartet in Eb K 428, end of last movement