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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] media-libs/libsidplay-2.1.1-r7:2::gentoo  USE="-static-libs" 1856 KiB
[ebuild  N     ] media-sound/sidplay-2.0.9-r2::gentoo  354 KiB

Total: 2 packages (2 new), Size of downloads: 2210 KiB