Everyone seems to be agreeing that music is a personal thing. While my personal choice on the river would be the same as when I drive through the desert; Lantz and Speer, Arkenstone, Carlos Nakai, etc.; I choose not to listen to them on the river and project my ambiance upon others. As mellow as my selection would be someone else might consider it inappropriate for the moment.
I guess it becomes tribal and to make sure you boat with people who prefer a common choice of music and river manners. If you have formed your own tribe then perhaps it becomes important to not impose your tribal customs upon other tribes. But, whatever.
Unfortunately, on the river/lake, I've been in the proximity of near license plate rattling boom boxes(most recent examples, adjacent Cottonwood Camp on Ruby Horsethief, weekends on the upper Colorado, sea kayaking on Colorado lakes). I'm sure rattling license plates is not the intent of some of the participants of this thread but just looking at these speakers makes me wonder (and they set off negative vibes in me).
Since music is a personal choice, please keep it personal and use headphones or earbuds. It seems like it should be as simple as that. If perhaps you want to share music then I'm sure it is possible to bluetooth among earbuds within perhaps a couple hundred feet; in effect, a local radio station (I must admit it would seem strange to see a tribe of people in various altered states playing air guitar, exploding grease bombs, shooting bottle rockets, howling at the moon, etc, without the accompaniment of a booming box(perhaps I associate to much with boom boxes
Signed, Party Pooper.
PS, I do enjoy the discussion of the engineering/electronics. One of my former lifestyles was such that I had to always be on call to support various mission critical earth science applications I wrote as an independent consultant. Hence, I had to maintain the charge in various ways on a sat phone. But my hopefully once daily calls on the GC, MF, Baja, etc were always done in a least offensive way possible.