Generally speaking, classical music compresses better than some other things(for classical ensembles at least).
There is no correlation between the "seriousness" of music - or the pretentiousness of it's listeners - and how well it compresses. What matters is how effective what's there is at masking other stuff.
Also, mp3 doesn't really do dynamic compression, at least not on a macro scale. I think there's a lot of confusion regarding this because your average "civilian" off the street doesn't really quite understand what dynamic compression is, and thus easily confuses it with data compression when "overcompressed music" is being discussed.
And it doesn't help that some audio marketing folks perpetuate this by always bringing up dynamic compression and loudness wars whenever talking about mp3's vs. CD vs. higher res (or whatever they're selling). This is helpful to them because though
we might understand that you can't fix an overcompressed recording once the damage is done, the general public might believe they can buy some doohickey to fix it, or that the problem is with the file format rather than the engineering and buying a more expensive "higher res" format is the only way to fix it even though it has absolutely nothing to do with the problem.