mpd initscripts needs the alsasound initscript, which is provided by media-sound/alsa-utils. Either the mpd initscript doesn't really require it, or the mpd ebuild should have media-sound/alsa-utils among its dependancy simple fix : add media-sound/alsa-utils as mpd depend.
Look inside the ebuild, the "need alsasound" is added to the initscript if alsa USE flag is on. This "hack" has been discussed in bug #99969. I have changed the alsa? dependency to alsa-utils instead of alsa-libs, as you suggest, to make sure the initscript is there when needed.
Closing as FIXED, thanks.
*** Bug 124459 has been marked as a duplicate of this bug. ***