Attached patch enabled me to emerge media-sound/museseq-0.8.1-r1 with gcc 4.3.1.
Created attachment 167274 [details, diff]
Enabled compilation of museseq-0.8.1 with gcc 4.3.1
Created attachment 167276 [details]
ebuild utilizing the gcc43 patch
Added src_unpack and applying the patch there. Also dropped the stable arches (wrt -r1, i.e., amd64 and x86) to ~arch. Maybe this ~arch business was unnecessary?
museseq-0.9 already has this patch applied.