Just for future reference, another way to achieve the same (which is mpv specific) is

play-music()
{
    local selected=($(find "${PWD}" -mindepth 1 -maxdepth 1 -type f -iname "*.mp3" | LC_COLLATE=C sort | fzf))

    mpv --playlist=<(printf "%s\n" "${selected[@]}") </dev/null &>/dev/null & disown
}