I just had this idea come to mind after I analyzed Grande Valse Brillante Op. 18 and asked if it was in Sonata form. What if I combine the Waltz and the Sonata? Here is my proposed form for the piece:
I call the piece that I am composing, Valse Quasi una Sonata, which translates to Waltz almost like a Sonata. As you can see from the image, I use the Dominant more as a bridge than a true Dominant. This is how I bridge to the Subdominant with the Dominant:
C major -> C minor chord(or the note Eb) -> Bb major
I have this bass pattern occurring throughout the piece:
Root, Chord, Chord
Often the 2 chords will be an inversion apart, but when the right hand gets into the bass clef, the chords are sometimes the same. The Root is usually at least a fifth down from the first chord, but particularly with the F major chord, I find that I can only do that when the melody goes up high. If it stays in the first octave, I have to have the first F major chord be in first inversion, a third up from the root(the F an octave below the great octave, F1, is just too low to be the bass note in my Waltz). The hardest part I have found so far about composing this piece is having the rhythm of the Waltz and the form of the Sonata, while keeping the piece coherent.
So, how can I keep the piece coherent when I am combining the rhythm of the Waltz with the form of the Sonata? Use melodic fragments from earlier in the Waltz in the Development(My Development sections tend to have a high ratio of new material to old material)? Have the left hand play the melody in the development, while keeping the Waltz rhythm going in the right hand?