Tuning question: Notes go flat during sustain

I'm curious to know if it's normal for notes to sound sharp at attack, and then turn "flat" as they ring and sustain.

I can pluck a string, and see it dead-on on the tuner, but decreasing in frequency -- fading out to ~-15 cents flat. Some strings rise quickly at attack, flatline and then drop off.

It's not a big deal, and I don't have a complex over it, but I'm wondering why that would be. Is this common to all string instruments, or just ukes, or just cheap ukes like mine?

Is it a clip on tuner?
If so, I am guessing that since the headstock vibration changes the tuner will also.

I use both.. I have a Peterson clip-on, a Snark clip-on, Cleartune Android app, and some other microphone tuners that mostly agree -- sustain flattens out.

Ground Loop said:

I'm curious to know if it's normal for notes to sound sharp at attack, and then turn "flat" as they ring and sustain.

I can pluck a string, and see it dead-on on the tuner, but decreasing in frequency -- fading out to ~-15 cents flat. Some strings rise quickly at attack, flatline and then drop off.

It's not a big deal, and I don't have a complex over it, but I'm wondering why that would be. Is this common to all string instruments, or just ukes, or just cheap ukes like mine?

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Most notes you play are played short (no sustain), so you only hear them for a short while, so they should be spot on in the beginning. Some reading material on the subject:

http://www.endino.com/archive/tuningnightmares.html

How old are your strings....

mm stan said:

How old are your strings....

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Are your stings new? If so, sounds like that are sretching.

Actually, this is perfectly normal on most any (plucked) stringed instrument. It's more noticeable on some than others, but always happens with plucked strings. When a string is plucked it is stretched - the harder it is plucked the more stretching occurs. As the note decays the string is not moving as far, so it is not stretched as much. I suspect this is why it tends to happen less noticeably with amplified instruments; with those you typically pick much more softly (letting the amplifier do the work) so there is less stretching and less noticeable difference between the attack and sustain parts of the note.

Because of the way the human ear works, and because you typically pluck the notes on the beats (and off beats), you want to tune so the struck part is on pitch and not obsess too much over the decay. Most people won't hear the pitch change in the decay, anyway. This way, everyone in the band is hitting the same pitch on the beats - imagine if everybody tuned so they were on pitch well into the decay cycle - because different instruments change pitch differently with regard to time, the notes would be all over the landscape for different members of the band just when being "together" matters the most - when the notes are struck.

John

OldePhart said:

Actually, this is perfectly normal on most any (plucked) stringed instrument.


John

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Great explanation. I'm imagining a big rubber band being plucked. Beee-uuu-oooong

OldePhart said:

When a string is plucked it is stretched - the harder it is plucked the more stretching occurs. As the note decays the string is not moving as far, so it is not stretched as much.

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Hah. You explain it that way, it almost seems obvious now. Sure 'nuff, plucking harder makes them sharper.
Thanks John.

(This also means I haven't been tuning well, since I've been focusing on the longer sustain to work the tuner while it settles.)