I am the Fedora packager of MuseScore. I tried to build the trunk against the latest libraries we have in Fedora rawhide, including qt-4.7, and the only problem I found was the missing linkage to librt and libdl.
Fedora does not allow implicit linkage in binaries anymore. Everything that uses a library must link to it explicitly. I am attaching the patch I made, which will fix the build failure of MuseScore on Fedora. Please consider applying it.