On Wed, Jul 28, 2010 at 9:48 PM, Niels Mayer <nielsmayer@gmail.com> wrote:

If you use KDE, the dolphin file-browser lets you preview any files
you select. Music files have a "previewer" that will allow you to
listen to any format recognized as audio, and optionally using
whatever "nonfree" plugins you might have installed for decompressing,
for example MP3.

See http://everyjoe.com/technology/dolphin-file-manager/ for a picture.

If you setup KDE's System Settings->Computer
Administration->Multimedia , you can set it up so that "Music"
applications will send the audio to a specified soundcard, but you can
also give priority to "Jack Audio Connection Kit" instead of a
specific soundcard, and then it will always send music via Jack. This
can be set on a per-task basis so that you can have VOIP always go to
a USB headset, and music always through jack, and video sound through
something else...

If browsing MIDI files, one of these days, kmid2 will be able to use
kpart come up embedded in dolphin to allow it to preview MIDI files
directly, but until then, clicking MIDI would launch kmid2 if you had
that installed. ( https://bugs.kde.org/show_bug.cgi?id=241220 )