I get the impression that the dynamic limitations of a less powerful amp may be less of an issue for non-classical music, which is less dynamic?
Yes, with some isolated exceptions here and there, well recorded classical symphony orchestra will have much greater dynamic range, and therefore require greater amplifier power, than pretty much anything else (including other forms of classical music, as well as the types you mentioned).
A particularly dynamic recording of classical symphony can easily have occasional brief peaks that are 30 db or more greater in volume than soft passages (30 db being a factor of 1,000 in terms of watts). Since it is typically the lower volume levels within that range that comprise most of the music, the volume control will be turned up to a much higher position for that kind of music than for, say, rock, most of which is compressed such that its volume varies over a range of only a few db.
So the occasional brief peaks in a well-engineered symphonic recording will demand much more power from the amplifier than pretty much anything else.
Regards,
-- Al
