The song in question is this cover of "I'm Just Your Problem" by our very own Elena from Spain (which I've linked on here before). Elena's version has been reblogged on tumblr over 60,000 times, and the original blogger never even said who the song was by. Dozens of people have been reuploading the song on youtube, and some of these uploads have even gotten more views than Elena's original video. Most of these did not include any credits, either because the uploader found it on tumblr and didn't know who it was by, or because the uploader forgot or didn't care to include them. And then quite a few people have even given credit for this cover to the wrong people, like saying that Karlos, the incredibly talented guitarist who performed the solo, was the one who recorded the song, or that the cover was done by Olivia Olson, the original voice actress for Marceline. Needless to say, it's been a very frustrating experience for Elena and myself (especially for Elena), as we've been tracking down all of these diferent posters, trying to get them to credit her correctly and put a link to her original video in their descriptions.
Luckily, quite a few posters have listened. Many of them didn't know who the song was recorded by (so they say), and have since included a credit and link to Elena's channel. But some of them still haven't, and some of them include the link way down at the bottom of a huge description and don't cite her as the artist who recorded it. So please, if you're ever going to reblog or repost or reupload something, MAKE SURE you include the proper credits to the creators, as well as links to the original source. This happens far too often on the internet.
P.S. I want to make sure none of you guys leave any angry comments on the reposters' pages, Elena has talked to each one and is trying to work things out with them. However, if you see another copy of this video that does NOT include any credits, fell free to politely tell the uploader to include them.