[mrob]

Another possibility:

- A music video that goes viral

I don't think Gangnam Style is a good match for the formula, but the video was well produced and just weird enough that people would want to share it. I'm convinced it only became popular because of the video.

[rainbowmverse]

The best part of Gangnam Style is it was a critique of what it became.

[bitwize]

Indeed. Even the lyrics read (in Korean) like a parody of Cake's "Short Skirt Long Jacket".

[poisonarena]

you are 100% right, a song without a video is just a track