This and other dances in general I have kind of been avoiding for the first 10 years that I composed. But I figured that if I am going to start composing dance music as well as sonatas, symphonies, and fugues, waltzes would be great to start with because the bass is very simple. I decided on a tempo of 90 BPM, so like Andante Moderato in the Italian terminology, to make it not so difficult for people to play once it is finished. I also decided on a key of D major because I compose a lot of my pieces in flat keys so I figured I should balance it out with some sharp keys.
I know these things about a waltz that apply more or less specifically to a waltz:
- Most have a 3/4 time signature(though some have a 3/8 time signature and others are at 6/8)
- Most are at a moderate speed(though I have heard some very slow waltzes and some very fast waltzes, Chopin's waltzes especially tend to be at tempo extremes)
- Left hand pattern is usually 1 bass note followed by the chord the bass note is in
- A lot involve pedaling, though not all do
- Waltz is dominated by melody
But I still find writing dance music to be hard, even though it is a shorter length composition than a sonata. Minuets are the hardest for me so far(I tried writing a minuet before and it didn't turn out well). My phrases and melodies in general also tend to be on the long side just like my speech. So I might end up with a 10 minute waltz instead of a 5 minute waltz.
But in a way, the dance being predominantly melody makes it harder to write than a sonata which is closer to equal in terms of melody and harmony. And there is no specific Waltz form(not even harmonically speaking) like there sort of is for the minuet(HC in A section, PAC in B section, PAC at end of repeated A section if it is there). But the most common form I see is ternary form + coda in a waltz, so I should probably stick to that for my first waltz. But theoretically at least, a waltz could be in rondo form or in sonata form.
The reason that melody makes writing dance music hard is mainly because there are so many possible melodies and in the case of a waltz, where the bass is super simple, it is like all my work goes into the right hand part and any sections where I have the left hand taking the melody and the bass I barely dedicate anything to because it is so simple.
Narrowing it down to melodies that start and end with specific notes, doesn't really help much because the melody could be 4 bars or it could be 10 bars. It could be sixteenth note dense, it could have no sixteenth notes at all. The rhythm could vary across the melody, it could be formed from rhythmic cells, it could be a mixture of the 2.
So how am I supposed to go about writing a waltz when there is burden of choice when it comes to the melody? Write the entire bass line first and then decide?