While working in an indie record shop back in the day I picked up a quick rule-of-thumb that had been developed by the owners of the shop and the chain.
In evaluating the credentials and potential threat of any rival shops or even other shops in other towns we would head straight for the Miles Davis section.
Most rivals would stock Kind Of Blue and a few compilations, possibly Sketches of Spain and some of his 80s ouvre.
These shops would not be marked as a significant threat.
However those who stocked an extensive catalogue of Prestige era goodies and stuff like Bitches Brew and the Jack Johnson album were considered to be more serious competitors.
Turns out that one could make a decent stab at evaluating the competition from one data point, and be right more often than not.
Indeed, scientists Peter J. Rentfrow and Samuel D. Gosling from University of Cambridge, UK, and University of Texas at Austin, in their paper The Role of Music Preferences in Interpersonal Perception back this up.
Their findings confirm that 'individuals use their music preferences to communicate information about their personalities to observers, and that observers can use such information to form impressions of others:
'[The study] revealed that music was the most common topic in conversations among strangers given the task of getting acquainted...
...observers were able to form consensual and accurate impressions on the basis of targets’ music preferences.
...music preferences were related to targets’ personalities,
...the speciﬁc cues that observers used tended to be the ones that were valid,
...music preferences reveal information that is different from that obtained in other zero-acquaintance contexts.
In addition we are reminded of this nugget from his book, Life, in which Keith Richards describes how he and Mick Jagger initially clicked, in the early days before the Stones even existed as a thing.
He notes that they had almost identical tastes in music (blues, r'n'b) and an almost telepathic understanding, and agreement on which music was right and wrong.
'... It was either that's the shit or that isn't the shit.
No matter what kind of music you were talking about. I really liked some pop music if it was the shit. But there was a definite line of what the shit was and what wasn't the shit. Very strict.'
On occasion we've employed the Miles Davis Heuristic in hiring situations.
When it's hard to choose between two candidates, equal on every level, then asking them to provide a list of their top five albums of all time can work as a tiebreaker.
On one such occasion a candidate blew it by offering up a Sting album in their list.
It was game over from that point.
Clearly, that isn't the shit.