Time Shift Surprise

Audacity 2.1.3.
Screen Shot 2017-06-02 at 18.34.51.png
The top two stereo tracks have been rendered to the third track. The goal is to produce a beat-matched overlap and shorten a musical segment. I did it by Time Shifting the second track to the left and a little skulduggery with fades. The track 2 area before the transition has been silenced with Command-L. It worked way better than I thought it was going to.

I changed the third track volume a bit and File > Export Selected.

I got my performance plus the shoved to the left silent time from track 2. Good thing I check these things before they go out the door.

I see Audacity and its arrows trying to tell me it might do that. Fair enough—we can chat about that. How do I export the track I hear, not the track with the formerly hidden silent segment?


Select the part of the track after zero, then trim, (Ctrl+T). The arrows disappear .
Trim excess before zero.gif

Select the part of the track after zero, then trim, (Ctrl+T).

Thanks. Why do I need trim? Wouldn’t Export Selected now work as expected if I drag-select the “real” track?

I couldn’t help wondering why Magical Time was included in my exported show.

We know Audacity traditionally has trouble with the Time Shift Tool. See: Export drops time if a track is moved to the right. I wasn’t expecting it to add time if I went the other way. Temporal inconsistencies abound.


Yes, that works.

Audacity export begins from the start of the audio. Whether the start of the audio is in “negative time”, or at more than zero time makes no difference - it’s from the start of the audio.
Whether this is the most useful behaviour remains a matter of debate, but that’s how it’s been for years.

that’s how it’s been for years.

So it’s been broken for years.

If I import my exported show, it will not match my timeline. That would be an undesirable undocumented feature.


“a matter of debate”

How would you describe the “correct” / “desirable” behaviour?

How would you describe the “correct” / “desirable” behaviour?

Playing my timeline matches the exported sound file I sent to the client.

Remember all the people who shipped carefully time-shifted clips to a finishing house and were surprised when Audacity didn’t export each leading segment of “no data?” It is expected that Audacity would preserve each of those time values.

This is the obverse of that.

Yes, I expect zero time to be the beginning of my show as all the other editors did.


Yes, exactly that. And you may recall that it is tied to the question of how “mix and render” works: https://forum.audacityteam.org/t/exporting-for-mixing/39199/1

and it was discussed here: https://forum.audacityteam.org/t/easiest-way-to-reassemble-wav-files-after-export/35096/1