Can't set the correct key when converting imported audio to GB loops

Question

Hi,
I feel I am really out of options for this one. I am trying to convert a couple of mp3 files to useful GarageBand loops. This is what I tried first:
1) drag the mp3 file on the timeline.
2) using a steady 4-beat, match the BPM settings to that it fits the tempo of the imported file
3) check the key of the imported file with a software instrument, and switch the project's key accordingly
4) Edit -> Add to Loop Library
Using this method, the produced loops show up in the Loops Browser correctly, but they play back in the wrong key. Example: I created a loop from a mp3 file that was originally played in A. I tagged it as being in the "A" key by creating a loop from it, with the project key set to "A".
When it then shows up in the Loop Browser, and I would select this loop with my Garageband project (still) set to "A" - I would expect to hear the loop being played in its original key.
It doesn't. It plays about four or five semitones too high (the difference between A and C, or C and E)
I haven't been able yet to figure out why this is so, or if there is any pattern in how much the key is off.
Then I searched far & wide, and found the Apple Loop Utility and a couple of articles on bulletsandbones.com. I also checked the midi import settings, though I doubt whether they have any influence here. They were set at 44.1 KHz.
This is what I tried then:
1) use bulletsandbones.com's never-fail conversion to AIF format (44.1 KHz sample rate, 16 bit)
2) use the Apple Loop Utility to "tag" the AIF file, setting it so that it shows up in the right category of the loop browser, etc.
3) also, use this utility to tag it with the key that the loop is played in
4) copy the AIF file into the Loop Library directory
5) start Garageband, and refresh / re-index the Loop Library so that the new loop is added and properly indexed
This made no difference. Or maybe it did, but the loops thus produced STILL do not play back in the key that I tagged them in (if I set the project accordingly, of course). It's completely mystifying.
I can omit a key indicator in the Apple Loop Utility, and only then does the loop play back as it should. But then it does not change with the project's key settings anymore.
Even more strange: even a loop that I tagged (in the "A" key) and saved with the Apple Loop Utility, plays back too high in that same Apple Loop Utility when I re-open it. It does play back correctly in Finder's Fast Preview.
I could not find any mention of this problem elsewhere. Does anyone have a suggestion what might cause this?

Answer 1

I think this is the culprit:
3) check the key of the imported file with a software instrument, and switch the project's key accordingly
If the "follow tempo & pitch" box is checked, this might change the sample's pitch and throw GB off.
Try to determine the sample's key before you import it, set the GB project's key accordingly, and then import the sample. That should assign it the correct key!