Indeed, Samurai would not meditate to loud music. However, use of meditation by warriors and/or martial arts experts is not "faggy" or "new age" nor would it likely have anything to do with mind control to convince soldiers to be hostile towards civilians.
日本*ピング* (kono risuto ni hairitai ka detai wo shirasete kudasai : let me know if you want on or off this list)
The consequences were, back in the old days, partial deafness.
Japanese musical advances have been made primarily in modern times where the use of antibiotics has minimized this source of damage to Japanese hearing.
So, let's put it this way, if the Samurai could have heard the music they might have used it to aid meditation ~ a little "Free Bird" perhaps?!