I want to be able to compose music in MIDI and play it back. I have Rosegarden and JACK installed (and working.. I think). I have ALSA installed and working, but I cannot get midi playback in Rosegarden, nor in KMid (once I made a MIDI file). I don't use a keyboard or any weird stuff, just composing it note-by-note in Rosegarden.

I read a few tutorials, but there is a lot of odd jargon that I don't understand (probably because I know little to nothing about MIDI and using keyboards).

What do I need to check ?

what kind of soundcard do you have ?

Sorry this took so long. It's an SB LIVE!

lspci says
02:03.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 07)
02:03.1 Input device controller: Creative Labs SB Live! MIDI/Game Port (rev 07)

alsamixer says
Card: Sound Blaster Live!
Chip: Cirrus Logic CS4297A rev 4

good answer

what you need to do is find the soundfont file on the windows install cd
mine was called CT4MGM.SF2
there may also be a CT4 and or CT8 version
use the largest one cause they sound better
put it somewhere on ypur harddrive mine i put at
/usr/local/lib/sfbank/CT4MGM.SF2

check and see if you have a utility called "sfxload"
which sfxload

if you don't have it you will have to get it
http://www.alsa-project.org/~iwai/awedrv.html
get awesfx

then you just (adjust path)
/usr/local/bin/sfxload /usr/local/lib/sfbank/CT4MGM.SF2
when i shut down i
/usr/local/bin/sfxload -i
to unload
and i put both of these cammands in my alsa startup script

ok, got all that, when I use sfxload I get "/dev/sequencer No Such Device"

You can create /dev/sequencer but that does not mean its actually working....
I have the same problem with midi playback. It just does not work. I can get it work but no actual playback.

that's the oss emulation

i guess show us
lsmod

i can't remember if we discussed if your system uses udev but if it does you need to load the sound modules at buut in this order

soundcore
snd
snd-emu10k1
snd-mixer-oss
snd-seq-oss
snd-pcm-oss
snd-seq-midi
snd-mpu401-uart