The term High Fidelity was coined with the word "fidelity" meaning the sound of reproduced music was judged in relation to the sound of, at the time of the phrase’s coining, the live-performances that had been recorded. That was the standard that both J. Gordon Holt and Harry Pearson used in their evaluations of both recordings (Holt was a good recording engineer) and Hi-Fi gear.
But that 1st-generation Hi-Fi crowd (World War II and Korean war-aged) was followed and replaced by boomers (Vietnam war and later), whose music was almost-exclusively studio recorded. In that context, High Fidelity has somewhat less meaning and relevance. Fidelity to what? Rock ’n’ Roll and other Pop music is recorded to sound "good", not accurate in terms of fidelity to an original acoustic event.
Gordon dismissed the use of recordings of electric guitar as material with which to evaluate Hi-Fi gear, arguing that there is no way to know what the recording should like. Younger reviewers, including John Atkinson, himself a player of electric bass (which he mistakenly calls a bass guitar ;-), argue that the sound of a Les Paul into a Marshall amp has a very well-known sound, as does a Telecaster plugged into a fender Deluxe Reverb, and Fender Precision bass into an Ampeg SVT.
My gold standard is vocals and acoustic instruments such as piano, guitar, upright bass, mandolin, dobro, fiddle, drumset & cymbals, brass (sax, trumpet) etc. I've played in bands with many of the above, and know the sound of them well. Sheffield Labs direct-to-disk LP's come mighty close to the sound of live Pop music.