Rather than alternative readings (as seen in manga etc.) I mean deliberate use of a more complex kanji in place of a simpler one, or use of kanji when kanji would not normally be used. A few examples:
(Smile by BUMP OF CHICKEN) 聲 used instead of 声; 'hard' kanji used in other words.
(空想メソロギヰ by 妖精帝國) Words that the goo.jp dictionary has an 'x' next to the kanji for...
(アイデンティティ by 椎名林檎) Lots of kanji here, notably for いる、ない、この and それ.
(Diabolos by DIR EN GREY) This appears to be a bit of kanji wordplay; 腐 is read 'ふ’ here, and appears to have no real meaning unless you look at the lyrics?
This (in my experience) appears to be ubiquitous, even for songs targeted at younger audiences (e.g. a 少女時代 song used 侮る, and I know at least one native speaker who can't read that - maybe a rare case). But of course natives are exposed to so much kanji, so can it be assumed that they can handle pretty much any ateji or rare kanji thrown at them?
And what is the effect that the artist is trying to achieve? I have been taught so far that using kanji unnecessarily comes across as either pretentious or overly formal (such as 有り難う御座います and the like)...