Comment 1 for bug 120810

A more complete reason:

* Starting TiMidity++ ALSA midi emulation...
ALSA lib confmisc.c:769:(parse_card) cannot find card ''
ALSA lib conf.c:3510:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:3510:(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:3510:(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3982:(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2144:(snd_pcm_open_noupdate) Unknown PCM default
                                                                         [fail]
invoke-rc.d: initscript timidity, action "start" failed.
dpkg: error processing timidity (--configure):
 subprocess post-installation script returned error exit status 1

This will start working if you reload your sound card information:
'sudo asoundconf list' to find the name of the card, and 'sudo asoundconf set-default-card' to set that card as default. Then, run '/etc/init.d/alsa-utils restart' to reload alsa, and then finish the installation. Everything should be fixed then.