That is completely false. The background music is easily doable:
/playsound music.game @p
Every sound argument you've put up with one or more numbers on the end is misleading.
Typing numbers on the end of sound arguments in the /playsound command will give you a false positive; it'll claim to play the sound, yet nothing will actually play.
I've easily made a better list of all actual /playsound arguments, where they all work up to Minecraft 1.8.8. It's accurate to the point where you can simply copy/paste the arguments into the command. I know this because I tested every last one of them myself. Hell, I've even already made an updated 1.9 version, and since they completely changed all the sound arguments for 1.9, it's an entirely new list!
And to summarize: If you're going to make a list of sound arguments that includes the numbers, TELL PEOPLE NOT TO TYPE THE NUMBERS INTO THE COMMAND! THEY DON'T WORK LIKE THAT!