Speaking as someone who has written one, books with titles like The Story of (insert band, genre, medium, era, etc.) in (insert number) Songs/Albums are often driven by ulterior motives. In my case, I had about 700 album reviews and used this format to shape them into what I hope was a fairly cohesive history of the rock LP called 33 1/3 Revolutions Per Minute. I don't know how successful I was, and I do know that the storytelling wandered off course pretty regularly, but I did make an effort to maintain that historical aspect throughout the book even though my real motivation was to turn all those reviews into a book.
Reading Punk in 50 Pieces, I could tell that Kevin Dettmar's main motivation was not to tell the history of punk through the lens of fifty essential songs but to analyze lyrics. I guess you could tell a cohesive story when analyzing the words of, say, Bob Dylan, which Dettmar has also done. It makes less sense when analyzing, say, "Hey ho, let's go, shoot 'em in the back now!", "Neat, neat, neat!", or "There goes a dogfish... meow!" And sometimes Dettmar seems to be seeing things that may or may not be there, like when he excoriates The New York Dolls for the misogyny of "Personality Crisis", a song as lyrically unfocused as so many others in this book. It may not have been very nice, but at least you could tell exactly what "Under My Thumb" was about. As much as I love 'em, most punks were kind of muddle headed, and analyzing their words is a bit like writing your doctoral thesis on a fifth grader's book report. And I'm not sure if there's much value in spending half the entry on Gary Numan's "Cars" describing how the song's been used in adverts.
I appreciate the challenge of writing a book of this sort, but I think Dettmar could have reigned in the cleverness and focused up to give the overarching story more dedicated attention. His historical context is usually limited to a few introductory lines in bold explaining the significance of the song before moving on to the lyrics.
Yet some of Punk in 50 Pieces works very well. Occasionally the author digs into a writer sharp enough to hold up to such analysis, such as Elvis Costello, Poly Styrene, and The Jam (although most of the author's nitpicks about "Down in the Tube Station at Midnight", easily one of rock's finest lyrics, are pretty easy to bat down...how are the song's attackers supposed to find the protagonist's house? Ever hear of a driving license?). Sometimes he puts a song in context very satisfyingly, as when he uses The Germs' "Forming" to discuss how some punks embraced lo-fi aesthetics, or when he uses X-Ray Spex's "Oh, Bondage, Up Yours" to discuss feminism in punk and McLaren and Westwood's SEX shop, the petri dish in which the UK punk scene germinated. Sometimes I learned something, as when the author explained the meaning behind the numbers in Tom Robinson's "2-4-6-8 Motorway" or detailed the drug-addled background of The Only Ones. Most meaningfully, he helped me resolve my feelings about one of my favorite songs, because I never quite believed Siouxsie Sioux when she professed that "Hong Kong Garden" was anti-racist, but Dettmar makes a pretty good case for her assertion's validity. Ironically, he also crystalizes his story whenever he digresses from his main structure to give some background on a fave punk totem, such as the safety pin or Doc Martens boots.
Such entries prove that with a bit more focus Dettmar could have delivered a book that fully "retells the story of punk's cultural earthquake", as the back cover copy of the proof I read crows, instead of just coming close to accomplishing that. These songs would still make an ass-kicking playlist though.