This sentence is from the theme song of an animated series called Kung Fu Panda: Legends of Awesomeness. You can find it on YouTube.
I found this question here: "A little something something"? but I don't think that the meanings listed there fit in the song. This Wiktionary entry and this Urban Dictionary entry didn't help either.
However, this Urban Dictionary entry might fit in the lyrics:
"Something something" means that whatever the person is talking about
isn't worth clarifying.
I also found a TV special of Family Guy called "Something, Something, Something, Dark Side" which is a parody of Star Wars. But I don't think that the songwriter wanted listeners to think that the series is made up of repeated ideas and things not worth mentioning. I can't think of another meaning, though.
Any ideas?
Best Answer
In addition to the uses you found we also use the word "something" to describe a thing that we can't remember or don't know.
For example, "I can't exactly remember what Alice said. She said something about 'the furious five' and 'alive.'"
This is a very typical use, but not exactly like the one in the song. In the song, "something" doesn't describe the forgotten word, it stands in for the forgotten word:
"Protect the valley, something (some word I can't remember), something (some word I can't remember), something (some word I can't remember), something (some word I can't remember) alive"
This is a common* way of singing a song, or quoting a speech, that you only partially remember. It's not formal, so don't use it in an essay for school, or a published article.
*The joke here is that we might expect that a viewer of a cartoon show would sing the theme song like this, because they could only remember some of the words. We would not expect the person singing the theme song on the show itself to have forgotten the words.