Things to consider when recording piano – and the electronic ones, too…
By Alex Case
If the piano were invented today, it probably wouldn’t catch on. A good one goes for $ tens of thousands, has no MIDI jacks (usually), weighs a few thousand pounds, needs constant (and laborious) tuning, and doesn’t come in a rack version. Sure, it sounds great—from gloriously rich and complex to aggressive and percussive. But it’s hard to play expressively, darn it; there’s no mod wheel, no volume pedal, and no vibrato.
While talents from Germany’s Beethoven to Peanuts’ Schroeder embraced the piano and helped it earn its place as one of Western music’s most important instruments, some of the issues described above have begun to take their toll. Courtesy of the convincing value and convenience of MIDI-triggered sample playback devices, the word piano often describes a set of synth patches, not an instrument full of wood, wires and felt.
Fair enough. Who amongst us is willing to hoist a piano into the back of the Subaru for our next general business gig?
Bowing to this reality, I’d like to share with you some thoughts on the piano. I have been lucky enough to work often in a studio with an exquisite 7-1/2’ grand piano. I’ve lived with it, recording it in rock, pop, jazz, and classical applications. I’ve also assisted dozens of engineers who have brought their own approaches to recording this same piano.
This article identifies the key insights from those experiences. If you haven’t had many opportunities to record a piano and really spend some time with one, don’t worry. Though it is a daunting instrument to record and mix, it pays rich rewards.
I’ll share some approaches to this enigmatic instrument so you can make accurate/beautiful/unique/weird/_________ (insert your preference here) recordings quickly, leveraging what may be limited (and pricey) time in the piano-equipped studio.
One man’s piano is another man’s…
You addicts of recording magazines have no doubt read an article or two about miking a piano: watch out for phasing anomalies, mic near the hammers for more attack, and so on.
Yet perhaps problems still exist. Let’s skip the hows and wheres of piano recording and evaluate the whys. Why place a mic so far from the piano? Why compress it?
Before the mics are placed around the piano, a more important issue should be resolved: what will the piano sound like? A piano in a room presents an opportunity to record any of a number of very different sounding instruments. Your approach to recording and mixing the instrument can affect the sound of the instrument dramatically. And as moving microphones is more time consuming than scrolling through patches, you should begin with a rather specific goal in mind.
It is essential to view the piano within the context of the song. What feeling are you trying to convey? What is the piano’s contribution to the story? How will it be placed in the mix?
These touchy-feely questions should be asked of all pieces of the arrangement of any pop song. The piano requires special attention because it is so darn flexible, as we’ll discuss below. It is the very definition of a full spectrum instrument. It’s capable of playing throughout the entire musical range.
And its harmonic content can easily fill the top, bottom, and middle of your entire mix. If the song ain’t solo piano, then the piano must leave room for the other players. That means, first, limiting the part itself so that it interacts with and complements the other instruments musically. Second, it requires restraining and shaping the timbre of the piano so it finds its place in the ensemble sonically.
Eq and beyond
I’ll leave the musical issues to the players, composers, and arrangers. But let’s look more closely at the sonic issues. It’s useful to consider the piano’s place in the mix along three broad categories: spectrum, image, and dynamics. These are loose categories with overlapping issues, but they do help us break the decision into useful components.
Spectrally, the piano can pretty much cover the entire audible range, from rich and warm low end to a shimmering high end and everything in between. Grand pianos thunder below 30 Hz while offering harmonics above 10,000 Hz. The most useful thing you can do to a piano on this dimension is to select specific regions to highlight and others to de-emphasize.
As always, the primary tools for accomplishing this are mic selection, mic placement, and equalization. Avoid the low end muck that occurs when a gorgeously rich, left hand-oriented piano part competes with a 6-string chorused bass over a kick/tom groove. Such a thick arrangement demands that something in the bottom two octaves (20 to 80 Hz) be sacrificed.
No problem for the piano. In this kind of situation, the piano holds up quite nicely without any bottom end. At the high frequency end of things, if you didn’t get to the tambouri ne or shaker part that you meant to add before the drummer left town, then you might be free to emphasize a tasty part of your piano sound anywhere in the 6 kHz to 12 kHz range; the delicate high end of a ribbon mic might be in order.
In the midrange it is important to pick your spots carefully. Vocals, guitars, and almost everything else need some space here.
If your music includes synths and samplers, you have no doubt experienced the horror of: The Synth Patch That Ate My Mix. Many patches—strings and pads are most often guilty—are mixes in and of themselves. They are nicely balanced from 20 Hz to 20 kHz and they fill the entire stereo image with their lush swirliness.
Thanks. Great sounding patch. But I’m writing a song here, not a pad. These sounds present an unmixably broad spectral content. And the piano can do the same if you aren’t careful.
There is a certain mic manufacturer based in Evanston, Illinois that makes a microphone often accused of being appropriate for any application. This includes the piano. Throwing a $100 mic on a multi-thousand dollar instrument might feel inappropriate, but it might sound just right. The presence emphasis of a Shure SM57 can pull the piano forward in the mix just as it does the Marshall stack.
But there is so much more to life than setting up microphones and twisting knobs on the eq. Make room sonically for the piano through careful use of stereo placement.
Improving your image
The stereophonic image of the piano sound is probably the best weapon for bringing clarity and unity to a mix. To discuss image for the piano, we need to understand what left and right mean. For a drum kit, left pretty much means the drummer’s left. However, since many drummers don’t know their left from their right, we often use the audience’s left as the reference.
Left and right are straightforward concepts for an orchestra—the conductor’s and audience’s definitions of left and right are the same and translate well to loudspeakers.
But what is left and what is right on the piano? Are we sitting at the piano bench (player’s perspective)? Or are we in the audience looking directly at the open lid with the piano player to the left (audience’s perspective)? Or, more fun still, are we looking straight down on a piano with the lid removed entirely (God’s perspective)?
With the piano, anything goes. There are no strict rules to follow, only creative options to pursue. Carefully defining the width and placement of the image will help bring order to your mix. The middle is always the trickiest. In particular, sorting out the competition for the middle frequencies can be made easier by thinning out the traffic in the middle of the stereo field.
Two approaches to consider are to isolate or to contrast. Isolation is achieved by panning midrange-hogging instruments (even stereo tracks of them) to different locations. The lead vocal and solos typically go to the center, and the rhythm section is placed hard left and right. Laws of pop mixing (which of course do occasionally need breaking) require leaving the vocal unquestionably front and center. Fine. Then put the guitars on one side and the piano on the other (see figure 1).
On the other hand, contrast is created by making one instrument spacious and enveloping with an image wider than the loudspeakers (fully panned stereo or doubled tracks, wide stereo reverb, stereo phaser/chorus effects) while the competing instrument is a more precise point in space (mono, dry, compressed). The piano is capable of both imaging extremes. Record and mix the piano toward a goal from the start, and it will find its place in the mix and be a more effective part of the song.
If it’s late at night and no one can tell their left from their right, don’t be afraid to track a mono piano. Often the “piano-ness” of the piano can be captured by a single well placed mic. Or a low-fidelity-by-design sort of sound might be the right vibe for the tune (does Wal-Mart sell microphones?). Open the lid and stick a mic right in the middle of the soundboard, starting about two or three feet above it, and you may find the piano sound that fits your mix (check out figure 2B).
The envelope please
Finally—and this is my favorite—consider the dynamics this instrument can offer. Again, I am leaving musical dynamics (mf decrescendo to pp, for example) to your musical judgement. Let’s look at mix dynamics.
Here I am thinking of the attack, sustain and fade of the instrument (see figure 3). All that time spent deep inside our samplers creating that hip didgeridoo patch is going to offer an unexpected payoff. Creating, looping, editing, and simply staring at sampled waveforms gives us a useful way to think about sound.
The shape of the sound wave (called the envelope) tells us how it might fit into our mix. Instruments fall somewhere on a range between clave (very short attack with essentially no sustain and nearly instant fade; the analog meter barely twitches) and rhythm electric guitar (you’ve no doubt recorded this and admired how the meter just sits at one level the entire song).
Sharp, spiky attacks will poke out of the mix naturally and needn’t be especially loud (this is particularly true for sounds panned far to one side). Smooth and continuous sounds need careful placement to remain audible without covering other elements of the mix. The piano, surprise, surprise, can cover quite a variety of shapes: percussion to pad.
Consider the attack side of the envelope. The very striking of the hammer against the strings in the piano is often emphasized through mic placement. The sharp attack enables the piano to cut through a wall of guitars; the contrast in envelopes (piano versus guitars) is the trick here.
But there is more than one way to sharpen the attack. Bring out that most wonderful studio toy, the compressor. Heavy compression (10:1 ratio or higher) with a medium to slow attack is all we need. The piano note sounds. Ten milliseconds later (or whatever attack time you dialed in) the compressor kicks in and yanks the signal down, changing the signal’s envelope.
Presto. The attack has been sharpened. Perhaps the attack was created entirely, a smooth and gentle envelope turned mean (as described in figure 4). Play with attack time, ratio, and threshold to find the kind of sound you want.
One idea is to try twisting the attack up to a very quick setting, leaving release at its quick setting and limiting the sound through use of a very high ratio. You’ll convert the piano into an almost bell-like sound: soft to no attack, with a very long, seemingly infinite fade.
But we’re not done yet. Consider the classical approach to recording a piano. Instead of close-miking the piano, distant pairs of microphones are typically used. This aesthetic values the sound of the piano in a hall. Perhaps it is better described as the sound of the piano and the hall. Distant mics are recording a greater proportion of the early reflections and reverberation in the hall and less of the direct sound of the piano itself.
Among other things, this approach gives you a radically different envelope. You can’t hear the hammers hitting the strings here. And the fade of the instrument is augmented by the decay of the hall’s reverb. In the home/project studio we approximate this through the careful combination of our sweetest reverb and a not too aggressive close microphone approach.
Of course readers in the back row will try it all: mics near the hammers, long hall reverb patch, and serious compression. Distortion and wah pedals are legal too.
But I ask that you consider first the sound you are going for and its appropriateness to the tune and to the mix. The piano welcomes radical approaches but demands careful control.
The ‘acoustic’ piano
There is no such thing as an acoustic piano. Pianos are by definition acoustic. If it’s a box full of silicon and solder rather than wood and wire, then and only then does it need the extra adjective (e.g. a ‘synth’ piano). Such are the rants of hopelessly romantic piano lovers like me.
But there is an important point to be made here. That heavy piece of wood and steel may be hard to move, but its sound is easy to shape. You may want an ‘acoustic’ piano sound that evokes the feeling and perhaps the image of an honest to goodness piano in an honest to goodness room. Or you may want a sound recognizable as a piano but aggressively manipulated to suit your creative desires.
We’ve discussed techniques for recording and mixing the piano toward a range of options. To be complete, let’s also consider the less expensive version.
The ‘MIDI’ piano
The alternative to the real-life piano is the ‘MIDI’ piano: the sampled/synthesized piano patches that live in synth racks. While usually owing some of their heritage to an actual piano somewhere in their past, these sounds are in fact pretty far removed from ‘acoustic’ reality. Let’s explore some of the spectral, image, and envelope opportunities these devices offer.
If your synthesis programming chops are sharp, you can really take the piano out spectrally. Hit it with some filters, run it through a distortion pedal, layer in other waveforms, and so on. Go to town.
The image of a ‘MIDI’ piano warrants special attention. Probably the most obvious peculiarity/feature of the ‘MIDI’ piano is the panning distribution of the notes. Each note of the typical piano patch occupies a location in the stereo field that very closely follows the position of each individual (ivory or plastic) key. This is standard, dare we call it traditional practice for ‘MIDI’ pianos.
With the popularity of synths and the impracticality of pianos, I fear that the true sonic image of a piano is being replaced with this synthesized/sampled non-reality. Surely those first samplers (…the humans recording the samples, that is…not the devices that regurgitate them…the samples that is…) noticed that the notes of a piano come from the entire piano, not from such precise points in space. The sound certainly doesn’t come from the blacks and whites themselves.
And the sound doesn’t laser beam its way from the string to your ears; it’s more vague than that. It is the soundboard, all 15 square feet stretching out before you, that radiates the sound. Both single notes and thick chordal voicings swell out from the soundboard (above and below it) swirling and bouncing throughout the structure of the piano and the room, finally reaching your ears as a complex soundfield in which the localization of individual notes is anything but discreet.
So what do we make then of this ridiculous panning paradigm that pervades our ‘MIDI’ pianos? Live it up! It is an opportunity. Real pianos can’t do this. Show it off. Utilize this convenience of sample playback to make better use of the stereo field. Clearly artificial effects like hard panned guitar doublings, ping-ponging vocal delays, and ‘MIDI’ piano panning are a great use of the two speakers you have to work with.
Warning: don’t pretend it’s a piano (an ‘acoustic’ piano). It simply isn’t. It can’t be. If your creative goal is a real piano, this panning algorithm can only be used as a special effect and it likely isn’t valid. If your musical desires include this type of stereophonic image, then don’t record a piano—record a ‘MIDI’ piano. They are two different instruments. Choose the one that meets the needs of the music and the mix.
Should you need a still more interesting stereo image, begin to tap the power of your sound module further. Chords needn’t sit still as a low to high, left to right image. Use LFOs or randomizing features to give your ‘MIDI’ piano a more varied sonic image.
Narrow the spread of the pan pots to exercise some control over a radical, motion-filled image and confine the total space of the image to a small region within the stereo field—for example, frenetic guitar arpeggios on the right, radical-hyper-swirling-virtual-piano on the left. When you use synth/sample playback units for pop music parts, anything goes—so go for it.
On the envelope front, ‘MIDI’ pianos offer us a particularly notable trick: reverse piano. Sneaking in with a gradual attack, sustaining with a rich piano tone, and ending abruptly, the reverse piano (my track sheets usually call this onaip) gives you a lot to work with.
Flip those samples so they play backwards, use a sequencer to get the part right, and you’ve got an attention-grabbing element in your arrangement—one that would be difficult or perhaps impossible to create with a piano. Additionally, synthesis makes it comparatively easy to accomplish other acoustic impossibilities. Tremolo and wah-wah are two directions worth exploring.
The mother instrument
The piano retains its significance today, despite it price, weight, and mechanical complexity. It is still the instrument on which many of us compose. It is the instrument in most every classroom at most every music school.
And as I hope I have communicated here, it has an important place in our gear-intensive pop music world. The piano on its own represents a vast range of sounds, an infinite bank of patches. I encourage you to explore the piano and all of its sonic relatives. You can get a lot of miles out of this one instrument.
Alex Case is a producer/engineer in New England. He is, ugh, a guitarist. Contact him via firstname.lastname@example.org.