# Which extended field should I use?
**URL:** https://community.mp3tag.de/t/which-extended-field-should-i-use/13934
**Category:** Support
**Created:** [September 26, 2012, 5:49pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934 "2012-09-26T17:49:35Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@jazzkovacs](https://community.mp3tag.de/u/jazzkovacs)
#### Post date: [September 26, 2012, 5:49pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/1 "2012-09-26T17:49:35Z")
Hi!
Here's the situation: I edited all tags for my mp3 collection, and added song key info (based on [Mixed In Key](http://www.mixedinkey.com) results, but manually) into the Comments field. I somehow hoped that Traktor Pro would "understand" it, and put the info into its own 'Key' field.
Obviously, it didn't. Comments are in the comments field.
If I could transfer these "comments" into a field called "Key" (via Convert Tag to Tag), all my problems would disappear.
The question is: which extended field should I use to put the key info in, that Traktor will recognise, and handle properly?
There is no 'Key', and I don't know what to choose. ☹
Maybe 'initialkey' is the one? Or am I wrong?
Any help would be appreciated!
All the best,
Laszlo
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### Author:  [@JJ\_Johnson](https://community.mp3tag.de/u/JJ_Johnson)
#### Post date: [September 26, 2012, 5:59pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/2 "2012-09-26T17:59:56Z")
Why not just try INITALKEY on a few files and see if it works?
If it doesn't, then try KEY and see if that works. INITIALKEY will create a native 4-character ID3v2 field named TKEY, while using "KEY" would create a user-defined TXXX field with a description of "KEY". Any time you write a field with a name that Mp3tag doesn't map to an ID3v2 frame, it creates a user-defined TXXX field for it.
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### Author:  [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [September 26, 2012, 6:05pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/3 "2012-09-26T18:05:50Z")
> [@jazzkovacs](#):
>
> ...Traktor Pro would "understand" it...
What does MP3tag have to do with a very particular function of that Traktor program?
Is it possible to save the key setting from that Traktor program in one of your files?
If so, you could inspect it after saving with mp3tag and you have the field name.
But it could be just as well that the Traktor stores these values in a database of its own... please turn to the traktor forum for clearification.
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### Author:  [@stevehero](https://community.mp3tag.de/u/stevehero)
#### Post date: [September 26, 2012, 11:31pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/4 "2012-09-26T23:31:56Z")
> [@jazzkovacs](#):
>
> Hi!
>
> Here's the situation: I edited all tags for my mp3 collection, and added song key info (based on [Mixed In Key](http://www.mixedinkey.com) results, but manually) into the Comments field.
Why do this when MIK fills either the comment tag and/or the INITALKEY tag and it does this automatically also. I think you need to read up on MIK software manual.
**EDIT:** MIK Version 4 _(Newest version is 5)_
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### Author:  [@jazzkovacs](https://community.mp3tag.de/u/jazzkovacs)
#### Post date: [September 27, 2012, 4:06am UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/5 "2012-09-27T04:06:24Z")
Thanks, guys, I understand _some_ of your comments...
**JJ Johnson** : this is exactly what I will do.
**ohrenkino** : Traktor handles the files when I add them to the Collection. The question was what to do _before_ importing, in order to have handled properly.
**stevehero** : I know what MIK does (and found out that it writes into initial key tag), but in this case, I analyzed my original wav files, and _then_ saved them as mp3s, so MIK had nothing to do with them. As I wrote: "added song key info ... manually."
Anyway, thanks for the suggestions, I will try to mess around with "initialkey".
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### Author:  [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [September 27, 2012, 4:37am UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/6 "2012-09-27T04:37:32Z")
> [@jazzkovacs](#):
>
> ...
> **ohrenkino** : Traktor handles the files when I add them to the Collection. The question was what to do _before_ importing, in order to have handled properly.
> ...
Well, it would not have done a lot of harm to add ONE file to traktor, do the keying stuff and then check with MP3tag what has changed. You then probably would have found the place where the programs stores the information: either in the file (= new field in the file) or in its database (=no new field in the file).
You check fields in the extended tags dialogue (Alt-T)
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### Author:  [@jazzkovacs](https://community.mp3tag.de/u/jazzkovacs)
#### Post date: [September 27, 2012, 4:54am UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/7 "2012-09-27T04:54:37Z")
Guys, 'initialkey' is the solution. I added MIK info (e.g.: 1A) to a file, imported itno Traktor, and... bang! Key is in the Key field!
Thanks for all your efforts! 😉
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### Author:  [@stevehero](https://community.mp3tag.de/u/stevehero)
#### Post date: [September 27, 2012, 7:57am UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/8 "2012-09-27T07:57:07Z")
> [@jazzkovacs](#):
>
> As I wrote: "added song key info ... manually."
Let me get this right. You run the wavs through MIK yet you decide to do this manually for mp3s when all you do is load your mp3 files into MIK and set it up to go to the comment tag. I sense you don't know how MIK works otherwise you won't have asked such a simple Q.
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### Author:  [@jazzkovacs](https://community.mp3tag.de/u/jazzkovacs)
#### Post date: [September 27, 2012, 9:07am UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/9 "2012-09-27T09:07:30Z")
> [@stevehero](#):
>
> Let me get this right. You run the wavs through MIK yet you decide to do this manually for mp3s when all you do is load your mp3 files into MIK and set it up to go to the comment tag. I sense you don't know how MIK works otherwise you won't have asked such a simple Q.
No, it's a little bit more complicated, and would be off topic to describe here. Trust me, I'm not that dumb that you think I am. 
Plus, my original problem has been successfully solved. 
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:24pm UTC](https://community.mp3tag.de/t/which-extended-field-should-i-use/13934/10 "2026-02-09T12:24:04Z")