Even with good quality musicians, your music will be "repetitive"
Even if not used directly by the game engine, its like giving a Rifle to a Crossbowman : If the guy can do amazing things with a crossbow, he can only do better with a rifle.
This engine allows "remixing". Ie .: See example 8 in the page, the guy took an already existing music (spy vs spy soundtrack) and made the engine remix it.
You can take small pieces of music and remix then on the fly, selecting then based on game events, and you will have the best of both worlds. Human generated music plus a incredible range of remix effects that makes the music never sound the same but have the same "aura".
If the java/license is a problem, you could use SoundHelix as a kind of external application or via the JNI. The licence doesnt matter as long as its downloaded separate (I believe even if the files are in the same download, as long as you dont mix dlls/jar with freespace code, you can send both in the same tarball, provided you make it clear the difference in licenses).
Sorry for my bad english, sometimes i have a hard time trying to make myself understandable.