On Mon, Nov 23, 2015 at 11:33 AM, jonetsu@teksavvy.com <jonetsu@teksavvy.com> wrote:

This "up-sample" as far as I understood from the course, does not exist
in reality as far as the quality of audio is concerned. A
demonstration can be easily made using Audacity and zooming up to see
the actual sampling points of both files, the original and the
"up-sampled": the file that has been resampled from lower sampling rate
will not add anything at all but more sampling points on straight
segments of the audio. It cannot add quality. It cannot create curves.

Your understanding is incorrect. Please watch this: https://xiph.org/video/vid2.shtml

If you have time (40mins to an hour), I'd also suggest you watch this): https://www.youtube.com/watch?v=BYTlN6wjcvQ
The meat of this one starts at 16:48 https://youtu.be/BYTlN6wjcvQ?t=16m48s but the preamble is worth watching for other reasons too.

Out of say 15 tracks, there would be 4 that need higher quality
sampling because they are acoustic instruments. But the 15 tracks,
even the synths and synth drums, will take so many more megabytes of
space, because the sampling rate is not set on a per track basis.
Maybe sampling rates on a per-track basis does not make sense in FAWs
in general.

your audio interface runs at one sample rate. all tracks not at the same SR would have to be resampled. Not a good idea.