When orchestrating piano music, it’s often best to think of this task in terms of translation rather than transcription, focusing on the core musical idea "behind" any (piano or orchestral) version, and asking:

What is the piano effect trying to create? How might this (or something similar) be best achieved by the orchestra?

What extra rhythms—and perhaps parts—could be extracted from the harmony, register, accents.

The several examples focus primarily on works that are well known in both the piano and orchestral repertoires, then end with my own orchestration of a piano piece by Bartók.

Some orchestral composers write for piano first, others write directly for orchestra,For instance, see Rimsky-Korsakov's Preface to his iconic Principles of Orchestration, 1891. while others still (perhaps most) sketch scores in a short-score format to begin with that is neither one nor the other. While composers use a variety of approaches, it will be most useful for us to focus on the first task: orchestrating from piano music. Among the reasons for this:

There exists so much wonderful music in both piano and orchestral forms.

It makes you consider closely the similarities and differences between two contexts.

It’s best to think of this task in terms of going back to the core ("pre-pianistic") idea and rewriting, re-realizing that idea for orchestra. You might like to think of this as analogous to translation, rather than mere transcription.

This chapter will begin with some basic principles, then move on to some magnificent examples of piano-orchestral pairs in the repertoire. I’ll finish by putting my own neck on the block, going through an orchestration of my own after a piano piece by Bartók.

Basic Principles

Firstly, start by reading the original closely—really closely. Ask yourself:

What is the piano effect trying to create? How might this (or something similar) be best achieved by the orchestra?

What extra rhythms—and perhaps parts—could be extracted from the harmony, register, accents.

Examples for extracting "additional" material from piano music include:

Extending notes: If the piano’s sustain pedal is down, you may wish to add parts sustaining each of the notes beyond their notated length (to the notated length of the pedal changes).

Extracting accents: Accents of all kinds can be separated off into separate parts in the manner of the "attack-sustain" effect discussed in the previous chapter, in which some parts play the music "as written," while others provide the attack only.

Examples that require reworking include:

Oscillating figures such as broken octaves. This is a pianistic solution that usually needs reworking for other instrumental forces. Many other instruments can repeat notes more readily than the piano. (Don’t forget to consider the register and rhythmic levels; as a rule of thumb, maintain at least those of the original.)

Arpeggiation. Large florid arpeggiations, by contrast, are better suited to the piano than most other instruments. You will likely want to break them up into multiple parts, dovetailed together to give the continuous impression of the original.

Brief examples

Let’s see this in practice with two examples from the piano repertoire. Consider how you would orchestrate them, then compare your result with the possible solutions below (but remember that there are always many different viable ways to do this—the solutions here are examples). Plan on realizing the Chopin example for string quartet and the Beethoven for classical orchestra.

Chopin: Prelude Op. 28, no. 13

Beethoven Op. 13

In the Chopin prelude, the left-hand distribution invites reworking for orchestral instruments. Here is a solution that re-distributes the material over two parts (viola and cello). Even if you decide to do some kind of redistribution in principle, there are a lot of different ways to realize it. I like this particular solution because it separates "main" chord notes (cello) from a broken thirds figure (viola), and in so doing, it brings out the very slight metrical dissonance hinted at in the original (here: \mathbf{^{12}_8} in the cello vs. \mathbf{^6_4} in all other parts).

You may have noticed an elephant in the room here—I’ve changed the key. Whether and when it is appropriate to do this depends on context. For an orchestration of all 24 preludes, it would be best to leave the keys as they are; in doing just one or two, we're freer to make changes like this move from F♯ to F in order to "fit" better on the string instruments, including hitting more open strings in the cello (which helps make some of the more unwieldly lines later on more practical).

Incidentally, earlier music is more likely to impel you to change keys between keyboard and orchestral versions. At least Baroque and Classical composers generally used a narrower set of keys for their orchestral works than they did in keyboard music.

Turning to the Beethoven, we have broken octaves in the left hand, a variable number of chord notes in the right, a crescendo, a growing tessitura, and some sfz chords. Here is a solution with viola, cello, bass, and timpani sharing that C pedal across three octaves and three different pulse values. Note also:

Where parts are added: first on the sfz, then twice in the next measure on the basis of motivic parallels and accelerating the rate of change.

The use of horns in E♭ and trumpets in C—a common device for composers of the time working with "natural" brass instruments (see the Fifth Symphony, for instance).

Transcription Case Studies

Now let’s turn to some longer-range examples, including some of the mo