Below is two different tracks containing the same rendition of "El vino triste" by D'Arienzo and Echagüe (1939).
The one at the top is from the album "La Morocha", made by the label Magenta. The one at the bottom is from the album "Juan D'Arienzo Vol. 6 (1939-1940)", from the Japanese label CTA.
The first thing to notice is that Magenta somehow has a shorter song. The difference is in the speed, from 69 BPM to 72 BPM.
The second thing to notice is that the amplitude is generally much higher on Magenta, and looks more saturated throughout the song. On CTA, we see more differences and room in the dynamics.
The same impressions can be found in the spectrogram:
I can almost feel how all this red must be terrible to listen to! Red pain! I do not want that when I play for dancers, nor for myself.
But, of course, all this would not matter if the human ear could not hear the difference. Here I give you two small samples, so you can decide for yourself!
First Magenta, from the album "La Morocha":
Then CTA, from the album "Juan D'Arienzo Vol. 6 (1939-1940)":
I think Google might have compressed my videos a lot, but at least we may assume the same was done on both... :-)
For more reading on this subject, I advise you to the following pages: