How much louder should I voice the melody compared to the accompaniment?

[ranjit]

I've recently become much more aware of the role dynamics play while playing the piano. I know that the melody is usually played louder than the accompaniment, but I'm now afraid that I'll make it too loud in comparison. Forte in the right hand and piano/pianissimo in the left hand? Or forte and mezzoforte? Also, if you're playing the melody pianissimo, it becomes very hard to play the accompaniment softer.

I find that my playing is usually best when I stop consciously trying to mould it and go with how I instinctively hear it in my head. However, I want to be able to be able to consciously figure out how to play it, and what exactly is going wrong in this regard, as opposed to waiting for a few hours/days and figuring it out by trial and error until it "clicks".

[quantum]

Dynamics are relative values.  Forte, fortissimo, piano, pianissimo... they all relate to one another.  It is not a measure of simply how loud you create your sound, but how it fits with everything around it and how it is reflective of the character of the music.  Forte in a percussive Prokofiev piece is different than forte in Mozart style.  Forte in a lyrical piece is different to forte in a driving allegro. 

Dynamics as a whole vs dynamics of individual layers.  Dynamic indications in the score more often than not refer to the overall dynamic, not the dynamic of each layer.  It is up to the musician performing the piece to adjust the dynamic of the various layers. 

Also, if you're playing the melody pianissimo, it becomes very hard to play the accompaniment softer.

Let's say this was for a lyrical Chopin Nocturne or similar piece, and the score says to play pianissimo.  In that case it would refer to the overall sound being pianissimo.  You are very correct in observing that if you play your melody pianissimo, the accompaniment would be difficult to play softer, as well as sounding ambiguous to the listener.  In that case you could play the melody mezzo-forte and accompaniment pianissimo, of course adjusting to the instrument and acoustic space. 

Quality of dynamic.  Forte can be round and grandeur, it can be edgy, it can be harsh and pleasant, it can also be harsh and unpleasant.  Pianissimo can be soft and velvety, it can be an impressionistic brush of colour, or it can be a gutless colourless murmur.  The quality of tone produced is also a part of the dynamic one chooses to create.  It is a large part of the character of the music one makes.  It is possible to play a lyrical piece with an overall dynamic perception of piano by singing the melody forte and playing the accompaniment piano.  This can work if the pianist chooses the appropriate tone quality: a singing and projecting forte reminiscent of vocal music, with a defined and supported piano tone. 

[samdm93]

I think it's quite a nuanced issue that isn't as black or white as playing each hand at a different dynamic, as the projection of the melody also comes from tone quality and touch.

A Chopin Nocturne is a perfect example of how this works. For example, the opening of the famous E-flat nocturne (op.9 no.2) is marked 'piano', so in this situation, you'd aim for the melody to played 'piano' and the accompaniment to be played 'pianissimo'. However, the projection of the melody doesn't just come from the dynamic difference between the hands, but how the touch allows the R.H to 'sing'.

In terms of knowing whether your melody is too loud - your ear is the only true indicator of this.

[mrcreosote]

I'd say the accomp. should never be noticeable or bring attention to itself - unless it is more than an accomp. 

A prime example of a varying range is Schubert Impromptu op 90 no 2:  some of the notes are distinct, others are barely audible.  So much dynamics in the accomp.  Listening to a beginner play this piece is pure torture, the accomp. played entirely too loud and without dynamics.

Further it is better to err on too soft  rather than too loud.