Thanks
Gotta give credit to the original artist/composer. Often what I do is go mix in audio from 1970s-90s military documentaries or training films.
Unfortunately, outside of the U.S. or allied government, the producers of these films rarely gave credit to the studio or composer they borrowed or purchased use of the music from. Often, these were well known studio composers (a lot of them from the UK) that did work for famous news networks or entities like the NFL.
I usually double check in Youtube if the music is already allowed for use and NEVER monetize my videos. Even if I had permission to do, I still never do it for I believe it takes the fun out of making these.