Worth checking exactly how well the ATC v. music override works.
I have a "music input" on my PS 7000 intercom, which works very well; it cuts the music immediately anybody (you or ATC) speaks, and then it gradually fades it back in.
It is quite cool to be cruising at FL180 over the Alps while listening to [insert your fav cool music
] but IMHO it is in practice of little use because the ATC activity makes the music impossible to listen to.
Of course if you fly truly non-radio (as opposed to flying with a listening watch) then it would work.