That presses your personal buttons very effectively, but it's not a universal button and - and this is the key point - it's not the greatest of all buttons.

Are there universal buttons? That there is any controversy at all over value of music so many thousands of years after its inception, and that music taste is tagged 'personal' (and indeed, uses words like 'taste' and 'preference') suggest there are not.

In the absence of universal buttons, how do we rank 'greatness' of buttons? Again, 'music taste is personal' is an impediment. There are several options:

• Ranked according to percentage of population affected positively (possibly minus percentage affected negatively)
• Ranked according to intensity of positive effect (possibly minus intensity of negative effect)
• Ranked as some synthesis of percentage and intensity.
• Ranked according to correlations with positive or negative traits, as determined by which traits increase or decrease fitness (musical tastes as an indicator of fitness)
• Ranked according to correlations with positive or negative traits, as determined by which traits increase or decrease social ability (musical tastes as a derivative of status and signalling)

The first three suffer from all the problems common to majoritarianism solutions - a self-approving effect (where the individuals who prefer 'what the majority prefers' make up the majority). The fourth is a pure evo-psych idea. The fifth is a twist on the fourth, but suffers to some extent from issues relating to cultural relativism ('greatness' of buttons is heavily dependent on current cultural settings).

Some of these systems at first glance seem to rank appeals-to-intelligence quite highly. Possibly appeals-to-desire-for-status could take top spot.