aries oryx # emerge -va qsampler

These are the packages that would be merged, in order:

Calculating dependencies -
!!! All ebuilds that could satisfy ">=media-libs/liblscp-9999" have been masked.
!!! One of the following masked packages is required to complete your request:
- media-libs/liblscp-9999 (masked by: missing keyword)

For more information, see MASKED PACKAGES section in the emerge man page or 
refer to the Gentoo Handbook.
(dependency required by "media-sound/qsampler-9999" [ebuild])

---------------

Dans /etc/portage/package.keywords

media-sound/qsampler ~* *
media-libs/libgig ~* *
media-libs/liblscp ~* *
media-sound/linuxsampler ~* *