The music you choose for cable listening tests should be exactly the same as for any main component. Assuming for the sake of argument (oh dear!) that differences do exist, then exactly the same piece of music will show if the the item is worth spending money on - be it cable or amplifier or whatever.
Personally, I choose albums that have okay SQ, but each have a problem: maybe a slightly brittle treble, or slightly lifeless sound. If a cable is to be a worthwhile investment, then it will make EVERYTHING better. The reduction in noise and HF distortions will tame a bright recording, whilst at the same time the increase in clarity will breath life into a dull recording.
If you have to agonize by repeatedly swapping cables to detect a minute difference, then walk away from it. Either there is no difference, or your money would be better spent elsewhere at this stage.
Personally, I choose albums that have okay SQ, but each have a problem: maybe a slightly brittle treble, or slightly lifeless sound. If a cable is to be a worthwhile investment, then it will make EVERYTHING better. The reduction in noise and HF distortions will tame a bright recording, whilst at the same time the increase in clarity will breath life into a dull recording.
If you have to agonize by repeatedly swapping cables to detect a minute difference, then walk away from it. Either there is no difference, or your money would be better spent elsewhere at this stage.