Armored Core - the first iteration of the series released in the US in 1997 involving customizable machines of war.
The music is somewhat memorable except for the sound effects drowning out the music sometimes but the intent was to capture all the destruction that would happen in battle. I really enjoyed the menu screen music that is the most memorable for me. So much so that I went out of my way to record it and listen without playing the game.
The game did not strike me as a winner until I actually gave it a chance.
If you have a chance to pick up this classic you will definitely learn the beginnings of Armored Core.