Day 4’s song is from Gigakoops, who has released a bunch of songs through C3! GK’s previous releases span a bunch of genres, from electronica-y indie rock (Two Door Cinema Club) to growl-y metal (iwrestledabearonce).

 
Here’s what Gigakoops has to say:

Today’s track is about as deep a cut as it’s gonna get in this pack. While I could have done one of Tool’s bigger songs, most are already available elsewhere, and I wanted to do a whole new song for this pack. It is also this author’s opinion that this song is one of their best, since it has such raw energy and driving force behind it.
As the presenter of today’s announced track, I feel it’s best that I let you guys get to know me a little bit. I am a fan of progressive rock, metal, and any experimental music, as well as electronic. So far I’ve released a few metalcore songs from Enter Shikari and iwrestledabearonce, as well as a few other songs in different genres, ranging from “Monster Mash” to “Bagger 288!” to name a few. Prior to C3, I worked both solo and with other authors in the RBN. I worked on the venue and practice sections on a few songs from TAG, including “Impulse” by An Endless Sporadic and the ridiculously titled “Let the Blood Spill Between My Broken Teeth” by Benighted, as well as the bass charts to “I Like Trains” by Lil’ Deuce Deuce and “Make the Sauce” by Vegan Black Metal Chef. I’ve also released a few songs I wrote myself, though back then my music seemed to be focused less on actually sounding decent and more on cramming as many notes in a measure as possible.
When I author songs, my favorite part would have to be guitar/bass, since those are the instruments I tend to play the most on Rock Band, and therefore have the most connection with. My least favorite would have to be the drums, simply because for me it’s too easy to mistake so many different sounds for something they are not. My overall personal policy for authoring is that realism in terms of notes matching up being the most important part, but the charts should also be as fun as they can be.
My personal favorite songs on Rock Band would have to be the overly-long epics, namely “2112” by Rush and “Veil of Illumination” by Andromeda. There’s just something to jamming out to a lengthy prog epic on Rock Band, especially if said songs are a fun challenge (at least it’s fun on guitar. Veil of Illumination Pt. 2 on keys would probably not be most people’s definition of “fun”). I tend to play with Xbox Live friends and fellow C3 authors whenever they’re up for it, and I also take my game to social outings among friends.
Thanks for letting me take the time to introduce myself a little better. Look forward to a lot of stuff from me in 2014, including some very well-known songs and even more stuff as obscure as Unicron (there’s people who enjoy the obscure shit, right? RIGHT?!).

(Remember, this is just a reveal; all of the songs will be released together on December 25. Check back tomorrow for another awesome song!)