Actually, Bassplay is my first ever Linux distribution, so it's equally probable I made some error while preparing it.
My mistake from the previous post - it should be /usr/local/include/bass instead of /usr/local/headers/bass! However, it seems from the code you posted that the problems occur at the linking stage. Check for the permissions for the libbas.so installed in the /usr/local/lib subdirectory - or try to change them by hand:
sudo chmod 644 /usr/local/lib/libbass.so
Then remove the directory unpacked from tarball and unpack the tarball again. Enter the directory and try to compile the source
I just got results similar to those you got by removing the reading permissions for libbass.so for all the users and groups, so I assume that if the library is in path and the linker still gives you unknown reference errors it might be the case of badly set permissions. Alternately, you can try to run both the configure script and the make commands with the as root (or via sudo), but the method I gave you worked for me only after I removed the directory unpacked from the tarball and unpacked it again (alternately, you can clean the project via make clean).
I hope this helps!