If you’re heading to Benicassim this summer then you’ve got a little over a month to get familiar with the acts on offer. There’s a number of fairly obscure bands playing this year, so it is wise to get on Spotify or Last FM and listen to as much as you can before heading out.
My advice is to make a festival playlist with all the music you can find that relates to this year’s line-up, play it on shuffle and just delete things from the list you aren’t keen on when they play. That way you are left with a reasonable list of the more obscure acts to add to the ones you were always planning on going to see. Simple.