I know there's two of these already:

https://modworkshop.net/mod/13693

https://modworkshop.net/mod/18334

but they're p old. One uses the grandpa .pdmod format, and the other is a .movie which both are not really relevant anymore to use these days(To my limited knowledge anyway). This is much smaller over the .movie version which I think broke and this has a good loop if your music slider isn't too high to hear the loop "crackle". Joys (and curse) of being an audiophile.

Just drop the Deus Ex Human Revolution Main Menu theme folder in your mods folder. Boot up and select it via Options > Sound > Custom Menu Tracks and off you go to meditation while making a build.

Sauce used for loop refining.