Welcome to the Piano World Piano Forums
Over 2.5 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

Gifts and supplies for the musician

Sanderson Accu-Tuner
Piano Life Saver - Dampp Chaser
Dampp Chaser Piano Life Saver
Grotrian Concert
for Pianoteq out now
Piano Buyer Guide
Acoustic & Digital Piano Buyers Guide
Who's Online
74 registered (agraffe, Anita Potter, anamnesis, AprilE, ascc, Arty Movie, 19 invisible), 1835 Guests and 16 Spiders online.
Key: Admin, Global Mod, Mod
Estonia Pianos
Estonia Pianos
Quick Links to Useful Piano & Music Resources
Our Classified Ads
Find Piano Professionals-

*Piano Dealers - Piano Stores
*Piano Tuners
*Piano Teachers
*Piano Movers
*Piano Restorations
*Piano Manufacturers

Quick Links:
*Advertise On Piano World
*Free Piano Newsletter
*Online Piano Recitals
*Piano Recitals Index
*Piano & Music Accessories
*Live Piano Venues
*Music School Listings
* Buying a Piano
*Buying A Acoustic Piano
*Buying a Digital Piano
*Pianos for Sale
*Sell Your Piano
*How Old is My Piano?
*Piano Books
*Piano Art, Pictures, & Posters
*Directory/Site Map
*Virtual Piano
*Music Word Search
*Piano Screen Saver
*Piano Videos
*Virtual Piano Chords
Topic Options
#657224 - 02/14/04 01:43 PM Rookie Question regarding Polyphony
T_bone Offline
Junior Member

Registered: 02/11/04
Posts: 5
Loc: Canada
All right ladies and Gentlemen... I am about to reveal my true rookie colors:

What role does polyphony play in producing sound in a digital piano?

I really have no idea what polyphony means, but it sounds important.

Thanks for the help... T_bone


Click Here

#657225 - 02/14/04 01:58 PM Re: Rookie Question regarding Polyphony
Matt G. Offline
3000 Post Club Member

Registered: 06/22/01
Posts: 3789
Loc: Plainfield, IL
T_bone, polyphony on a digital keyboard refers to the number of tones that can be produced simultaneously. Let's say your keyboard has 32-note polyphony. With the sustain pedal depressed, play a big chord, then continue to hit other notes. You will soon start hearing the notes of the big chord you first played drop out, because you ran out of tones that can be produced simultaneously.

Depending on the instrument, you must also be cautious with low polyphony specifications because some of the sounds on your keyboard may require more than one "tone" per note played, meaning that your ability to have a relatively small number of notes sounding together could be seriously hampered.
Sacred cows make the best hamburger. - Clemens

#657226 - 02/14/04 02:02 PM Re: Rookie Question regarding Polyphony
Zymtil Offline
Full Member

Registered: 04/13/03
Posts: 433
Loc: CS, Texas
Polyphony basically refers to the number of notes that can be played simultaneously. Althought, one must keep in mind that playing one note may eat up more than one note of polyphony.

#657227 - 02/14/04 02:16 PM Re: Rookie Question regarding Polyphony
Zymtil Offline
Full Member

Registered: 04/13/03
Posts: 433
Loc: CS, Texas
Matt G.,

Here's a couple quotes from past disscussions:
JimM: This is a very complex subject. Let me see if I can add to the confusion.

Your piano has a number of sampled sounds hard-wired into its memory. The sample was created by playing a note and recording it. Better samples record it at several velocities, let it ring longer, record more notes without interpolating sounds (up to 88 for a piano) etc. The note is the full sound spectrum.

The piano's software tweaks these samples in a variety of ways to create the instruments you get when you press the appropriate button. Some of the tweaking can use up more than one note of polyphony. Layering is an example of this. The only way I know to tell if an instrument is layered is to read the manual or look at the programming. Other tweaks don't consume polyphony - they add reverb or other effects, change the sound's envelope, etc.

For a basic piano sound, the usual relationship is one note = two voices of polyphony because the sounds are sampled in stereo. So if you play a 4-note chord you'll use up 8 voices. If you hold the sustain pedal down and then play another 4-note chord you're now using 16 voices because the first 8 are still sounding. Get the idea?

So does a choir use lots of voices? Not necessarily. If they sampled, say, a full choir singing in stereo, then each note might only take 2 voices. But if they sampled soprano, alto, tenor and bass voices and then layered them for a "full" choir you might use 4x2=8 stereo voices per note.

Most of this has very little to do with the "advanced" technology of the piano or lack of it. Better instruments typically have bigger and better samples so the sound is richer, lasts longer, whatever, but the basic polyphony issue remains 1 note = two voices. Usually.

Note-stealing happens when the piano runs out of polyphony. Different manufacturers handle this differently. The easiest algorithm is "first in, first off" - that is, the oldest sound is cut off first. There are other ways of doing it that are more complicated and may take more processing power, so I guess that's a place where faster computers help. Modern note-stealing techniques are pretty good.

Bottom line: more polyphony is better; 64 notes is probably good enough for solo piano; complex orchestrations want more than that; note stealing works OK for most things.[/b]
SteveY: JimM addressed this subject well, but I suspect that there are still a few misconceptions. I'll try and shed some additional clarity on the subject:

Let's consider some terminology first. The type of sound that your keyboard creates (a piano for example) is called a "Patch" or an "Instrument". This "instrument" is made up of "tones". Tones are individual "samples" or recordings of acoustic instruments -- in this case a piano. In order to recreate the sound of an acoustic piano with any sense of realism, multiple recordings/samples are used. These samples are typically layered (as many as four deep) in order to create a realistic piano sound. It's even common to trigger a different set of tones depending on how hard a key is played. One "tone" usually equals one note or voice of polyphony. JimM is correct in saying that sometimes keyboards contain stereo samples. In that case, one "tone" would equal two voices. However, while virtually all keyboards made today play in stereo, most samples are actually mono. They are "converted" to a stereo signal as they go through the keyboard's onboard effects processor.

So in the most typical case, a single key played is using anywhere from 1 to 4 notes of polyphony. A keyboard's processor has nothing to do with how many tones make up a given sound. It has everything to do with the sampling technique and the choices made by the sound designer. I believe that this was pointed out earlier, but the use of the sustain pedal uses up polyphony as well. A 6-note chord played with a 4-tone patch/instrument will use 24 notes of polyphony. When the chord changes, if there's any overlap in the chords due to the sustain pedal, that number can double instantly. 64 note polypony should be enough for a solo piano assuming that the player has good sustain pedal technique. But as others have said, when you add MIDI sequencing to the mix, 64 may not be enough.[/b]

Piano & Music Accessories
piano accessories music gifts tuning and moving equipment
#657228 - 02/14/04 05:05 PM Re: Rookie Question regarding Polyphony
fr Offline
Full Member

Registered: 06/14/01
Posts: 110
Loc: illinois
Polyphony is an issue that affects digital electronic pianos but not accoustical pianos. It is the number of sounds that can be heard simultaneously usually expressed as a power of two. The higher the number, the better but it costs more. 128 is the current benchmark. Don't buy anything with less than 64 notes of polyphony. Think of a digital piano as being a keyboard with a laptop computer inside of it. The digital piano (computer) runs at a certain operating speed and has only so much computer memory to reproduce sounds which is why polyphony is an important issue with digital pianos. Too little polyphony and you'll notice notes decaying earlier than they should such as in a densely noted measure using the sustain pedal.

Much has been said about this subject and you might want to browse this forum's topics concerning polyphony, especially the topic called "Polyphony - how much is enough" from a while back:


Moderator:  Piano World 
Piano Acc. & Gift Items in
Piano World's Online Store
In PianoSupplies.com ,(a division of Piano World) our online store for piano and music gifts and accessories, party goods, tuning equipment, piano moving equipment, benches, lamps Caster Cups and more.
Free Shipping on Jansen Artist Piano Benches
Pierce Piano Atlas

A. Geyer Pianos
A. Geyer Pianos
Lindeblad Piano
Lindeblad Piano Restorations and sales
Pearl River
Pearl River Pianos
New Topics - Multiple Forums
History of the piano - contemporary sales figures?
by Saranoya
Yesterday at 07:35 PM
Wanted -- guide to 7th chords (and inversions) for all keys
by BWV 846
Yesterday at 07:22 PM
An eagerly anticipated recital by Daniil Trifonov
by Hank M
Yesterday at 06:22 PM
High pitch static noise on digital piano - Yamaha-CLP 545
by Scandal
Yesterday at 05:06 PM
My Music!
by davidwest92
Yesterday at 04:54 PM
Sheet Music Plus
Sheet Music Plus Featured Sale
Forum Stats
87,140 Registered Members
44 Forums
178,596 Topics
2,610,177 Posts

Most users ever online: 15,252 @ 03/21/10 11:39 PM

Visit our online store for gifts for music lovers

Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
Our Piano Related Classified Ads
Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter |

copyright 1997 - 2017 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission