Is there a way to change the music of oblivion using your own songs or in a mod?

http://www.tesnexus.com/downloads/file.php?id=26892

What about our own music

As long as it does conform to a certain format, "every" MP3 file you put into one of the music sub-folders ("explore", "public", "dungeon", "battle") will automatically be added to this playlist and randomly used by the game as if it was one of its original tracks. In contrast to some installation instructions stating otherwise there's no need to rename any of these files, the game doesn't care. The only time renaming is a valid step is when wanting to get rid of some original tracks. But then, moving them away or deleting them would do the same, so...

As for different playlists than those 4 Vanilla ones, played under different circumstances etc., that's something which will require the BMS you were given links to already.

Oh and, the BMS is just an extension. It will still require "our own music" placed into its folders to do anything.
Of course then it might have some different rules to apply to when adding your own music to its system, but this should be well documented in the readme.

For just having your own music tracks played when wandering around through the country or the cities, venturing into dungeons or while fighting a fierce battle, simply put them into the respective folders.

drake is correct
although i've noticed this has a small but notable impact on performance