Try to find _mididings.so in your system and do ldd command on it.
stefets@PC1:/usr/local/lib$ ldd /usr/local/lib/python2.7/dist-packages/mididings-2015+rbbec99a-py2.7-linux-x86_64.egg/_mididings.so
linux-vdso.so.1 (0x00007ffe75cca000)
libboost_python-py27.so.1.65.1 => /usr/lib/x86_64-linux-gnu/libboost_python-py27.so.1.65.1 (0x00007fc60fd0f000)
libboost_thread.so.1.65.1 => /usr/lib/x86_64-linux-gnu/libboost_thread.so.1.65.1 (0x00007fc60faea000)
libasound.so.2 => /usr/lib/x86_64-linux-gnu/libasound.so.2 (0x00007fc60f7e3000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fc60f45a000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fc60f0bc000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fc60eea4000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fc60ec85000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fc60e894000)
libboost_system.so.1.65.1 => /usr/lib/x86_64-linux-gnu/libboost_system.so.1.65.1 (0x00007fc60e68f000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fc60e487000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fc60e283000)
/lib64/ld-linux-x86-64.so.2 (0x00007fc6102f1000)
Hope this help !
Stephane Gagnon