Good man.
I've a question - why are so many of the adverts on Korean tv accompanied with a song that sounds like a rip off of Sigur Ros Hoppipolla?
A reasonable question.
The answer is that many companies here as of late really like piano ostinato lines accompanied by dramatic build ups and stuff to add emotion to ads. Variations on Coldplay's Clocks (some ridiculously blatant) were another local commercial phenomenon that saw about 3-4 different appearances (from different companies) from 2008 to 2010.
I won't beat around the bush (since you've probably heard my SIII ads more than once)...In no less than three promotional pieces (although 2/3 weren't for TV) I wrote in the past 2 years for a number of different clients I was requested to use Hoppipola as a primary reference, and had to take an extreme amount of care to skirt the melodic phrasing and predictable chord inversions to avoid trouble, through it all discussing all relative components (use of a different melody's motif in specific repetition, contrasting overall melodic phrasing, completely different chord progressions) with musicologists and promo staff to steer clear of trouble. As someone who was active in the K-Pop scene for over 15 years as a songwriter/arranger, I can tell you that unlike many a peer, I have always refused to rip-off another artists (a few times to my undoing), but I know how to recreate arrangement elements in a song that will leave similar impressions...Which ultimately is the goal. I have simply trained myself to know how to steer clear of danger, and the following three principles are always on my mind:
1. Don't be an idiot and copy melodies. Ever.
2. Similar chord progressions (even while using a reference piece's choice of instrumentation) are "safe", but non-musical people invariably WILL cry foul.
3. Play it safe, even when told to do otherwise.