I wouldn't buy music just for hi-fi, not sure who would, but I have noticed my Cyrus system does sound particularly good with certain CDs. I guess this has had an impact on what music I buy now, but only slightly.
I have got a drum & bass CD which has a few tracks made purely of bass tones, they will 'work out' your hifi. The sub-30Hz track is barely audible, it's an excellent 'work-out' for my Trace Elliot bass amp which in turn is a good work out for my neighbours bowel system.