playing an Mp3 from Rev

[Kurt Kaufman]

"...can anyone recommend me a different audio file type
that is not so memory-eating but that Revolution handles as well as
Mp3s?..."

If you do not need stereo sound, you can get decent sound quality at 
about .7 MB per minute by using the following settings:
IMA 4:1  (that's AIFF-C, I think)
at 22.050 kHz, mono, 16-bit

Using the above settings in stereo will of course take up more disk 
space.

"...also, how does one edit sounds in Revolution, like control the 
volume,
etc?  Or even record and edit sounds like we used to be able to do in
Hypercard...  is that possible with Revolution?..."

See the documentation entries for, among others:
record sound
playLoudness
recordLoudness  (there's your "VU" meter)

I don't know if it is possible to edit a sound file from within 
Revolution.  If the showSelection property of a player is true, you can 
easily manually select a portion of the file to play.  Or you can also 
specify a startTime and endTime in your script. So, you could keep the 
sound file in its original state, but play various segments in whatever 
order you please by setting and resetting the startTime and endTime.
I don't recall seeing QT-Pro style selection markers on the Revolution 
QT-player controllers (gasp!). Of course, you could edit the sound file 
as binary data (double-gasp!....just joking; I don't suppose that is 
very practical).

-Kurt