I recently heard the U.S. Marines Band (The President's Own). Although the selections weren't among my favorites, I did enjoy the concert and have three observations:
1) The level of musicianship of the band is very high.
2) I forgot to take my SPL meter, but from my seat in the balcony in this 1000-seat hall, the music was louder than any live orchestral music that I've ever heard (which, of course, is usually performed in larger halls). I covered my ears for almost half of the concert.
3) I've often wondered if the Fennell/Telarc recordings exaggerate the bass drum. NO! The bass drum in this concert was even more prominent than in the recordings although the band was playing extremely loudly.
Jan