I've written Slackware build scripts which you can use to get Musepack SV8 natively compiled for your system and architecture. Not to mention the benefits native Slackware packages bring (easy installation, removal, tracking etc).
I've submitted them to SBo.org (http://slackbuilds.org/) but it can take quite a while for scripts to get approved so I am announcing it here for immediate benefit.
You can find them here: ramov.com/sbo (http://ramov.com/sbo). Enjoy!
Hmm, I can't seem to be able to edit the post, I've forgot that I have Slackware specific domain for these things. As of now, the correct address is slackfu.com/sbo (http://slackfu.com/sbo).
P.S. Also, you first need to install the libraries and then musepack-tools afterwards.
I am happy to announce that complete collection of SV8 Musepack tools and libraries (libcuefile, libreplaygain and musepack-tools) is now officially part of SlackBuilds.org (http://slackbuilds.org/), which is also a preferred place to get them.