There are some great Rosegarden tutorials on the Internet and even some specifically dedicated to making sound using Rosegarden, e.g. this sourceforge tutorial. However, it took me quite some time to discover how to do it easily, on FC7, so here are some short easy notes that are up to date as of mid-FC7, but do not require the user to understand all the complexities of Rosegarden, ALSA, Jack etc.

Of course, the simplest way of getting sound out of Rosegarden is just to export your composition to a MIDI file, then to use timidity++ (or another suitable MIDI synthesiser) to play it. This guide uses a relatively simple arrangement of just three programs, like this:-

1. That you're using Fedora Core 7 (FC7) with SELinux disabled.
2. That you have an Internet connection so that you can use yum.
3. That you are using KDE, since Rosegarden is a KDE application.
4. That you do not have a sound card that supports MIDI directly.

su -
yum install qsynth jack qjackctl lilypond rosegarden4 perl-XML-Twig

## Automatically appended by jack-audio-connection-kit
@jackuser - rtprio 20
@jackuser - memlock 4194304

## Automatically appended by jack-audio-connection-kit
#@jackuser - rtprio 20
#@jackuser - memlock 4194304
*       -       rtprio 20
*       -       memlock 4194304

3. Get some sound fonts and install them in Qsynth
The tutorial that I referred to above suggests getting some sound fonts from here.

4. Match settings in Jack and Qsynth
Here are some settings for qjackctl and qsynth that seem to work for me using an AMD 64 3500 (64 bit) on FC7 with a kernel-2.6.23.8-34.fc7 kernel. The important thing is to make qsynth and jack compatible with each other, or you will get no sound. Start qjackctl and qsynth from the KDE menus in that order.

Note the command 'artsshell -q terminate' in the qjackctl setup window above. This is useful because it kills the KDE sound daemon that would otherwise prevent jackd from talking directly to ALSA (in other words you would get no sound, and perhaps an error message.)
Also, and this is important, make sure that the 'Start JACK audio server on application startup' box is ticked under the Misc tab in the qjackctl setup.

The entries 'Force 16bit' and SampleRate=48000 particularly need to match in qjackctl and qsynth. Others may require some experimentation to get your sound sounding good. The entry, Interface=hw:0, will often make the difference between sound and nosound.

Remember to enable MIDI input in qsynth. That's what it's for :).

5. Check that the Rosegarden settings are sensible

Tell Rosegarden to use the Jack transport.

No need to tell Rosegarden to start jack, as we will see in a minute. N.B. that the Jack Command is not needed if this guide is followed fully.

6. Test your Rosegarden, Jack and Qsynth Set-ups
From the KDE menus, start in this order: qjackctl, qsynth and rosegarden. There should be no error messages. The jackd transport should start automatically. Load a file into Rosegarden and hit the play button. The MIDI output from Rosegarden will immediately become sound! :) If not, turn on the log files in qjackctl and qsynth and start debugging or googling. If you get xruns in the jack log file and horrid sound quality, you either need to fiddle with the jack and qsynth setups, or you need a faster processor :(

#!/bin/sh
# V1.0 DWL 22/12/2007
qjackctl &
sleep 2         # Wait for qjackctl to start jackd
qsynth &
rosegarden --nofork
#
# Kill qjackctl, jackd and qsynth when rosegarden exits.
ps -ef | grep qsynth | grep -v start | awk '{print "kill -15 " $2}' | sh
ps -ef | grep jack   |                 awk '{print "kill -15 " $2}' | sh
exit;

Please send any improvements to this guide to dwlegg a t gmail d o t com.