I have built ALSA/OSS as modules and followed the howto on ALSA's page and still the sound is not working.
justin@crusoe:~/mp3s$ mpg123 youngbloodz\ -\ cadillac\ pimpin.mp3
ALSA lib confmisc.c:550

snd_determine_driver) could not open control for card 0
ALSA lib conf.c:3463

_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:387

snd_func_concat) error evaluating strings
ALSA lib conf.c:3463

_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:945

snd_func_refer) error evaluating name
ALSA lib conf.c:3463

_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:3932

snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2068

snd_pcm_open_noupdate) Unknown PCM default
No default libao driver available.