chord progression you already have? like accompanient in reverse

I would just improvise over the progression and see what comes up.

I would listen to the chord progression over and over, and just listen to what comes up in you, don't be what bach called a 'klaviercomposer' :), best ideas come from your head, not your hands.

Pitfalls you should watch out against include (a) the assumption that you are restricted to notes belonging to the chords only and (b) the assumption that all chord qualities are equally suitable for all melodies. Neither is true and both severely restricts the range of melodies perceived possible for a particular progression.

Play around with the quality of each chord, and you may find that you get different ideas depending on which series of chord qualities you use. Both the open and close nature and the different inversions mean that the melody will end up making a different set of intervals with the accompaniment, and this is what - in large part - defines your music.

Having a melody not belonging to a chord transiently modifies the chord for the duration of the note. It is perfectly possible to put, for example, an F over a C major chord, and alter the accompaniment so that the F of the melody never comes together with the E of the C major chord, thus avoiding dissonance. Play around with how you might introduce the notes making up the chord in relation of how you might imaginarily introduce the notes making up the melody. It's a reciprocal and iterative process. You come up with a good melody in response to a chord, tweak the way you introduce the chord notes, tweak the melody, tweak the accompaniment, ..., until you're happy with both the progression and the melody and their combination.

I'm not a big believer of abstract explanations. If you post concrete examples then I'm sure composers on this Forum will gladly have a stab at "melodising" your harmony.

Great post, very informative, thank you Tar.

I like to start with the melody first and make the chords work around it.....what helps me is all the music I have played over the years is somewhere in my brain and then my inner-ear can play with all sorts of ideas. Thank-you to all the great composers...then and now.
rada

did bach actually say that?

I wondered that too. It's interesting if he said that given what a brilliant improviser he was!

I couldn't find it in the english wikipedia, but I didn't such all that thorough, in the dutch wikipedia it sais:

Improviseren op het klavier als een manier om te componeren werd afgeraden; Bach sprak met minachting over wie hij noemde de 'klaviercavaleristen' die hun vingers op zoek naar ideeën over de toetsen lieten gaan.

which roughly translates to

Improvising on the keyboard as a manner to compose was not advised; Bach spoke with contempt over who he named the 'klaviercavaleristen' that let their fingers search over the keys to find ideas.