What distro are you running?
The instructions from the README file are the instructions on how to build the binary files for mp3blaster. It looks like you downloaded the source code for the application.
There are different ways to install an application in linux. The method you use depends on the distro, and your experience level.
Most distros with a package manager install pre-compiled binary code, for that distro. Examples, Ubuntu, Mandriva, and Fedora Core. The package manager looks after the dependencies for that package, and relieves the user from the task.
Some of the more advanced distros provide the source code, and you need a group of programs and libraries installed in order to build the binary files. This is usually done by more experienced users.
There are lots of programs around that will play mp3 files, xmms, Beep-Media-Player, just to mention two.
That program runs as a text application in a konsole, from what I have read. Is that what you want?