Just one of the unexpected bits to be gleaned from Finishing the Hat: Collected Lyrics (1954-1981) With Attendant Comments, Principles, Heresies, Grudges, Whines and Anecdotes is that Stephen Sondheim describes himself as a “lazy reader.” The hyperliterate master of the rhyme and musical reason, intrepid juggler of the vowel and consonant, doesn’t particularly enjoy reading books. Would never have imagined it.

Perhaps those who have struggled with poetry (which he is quick to distinguish from lyric writing) would most enjoy the chapter “Rhyme and Its Reasons,” an analytically fascinating examination of perfect rhymes and near rhymes and why, for example,  “weary” and “bleary” are a less effective pair than “weary” and “eerie.” In this compendium, ranging from his first show, Saturday Night (1954), to 1981’s Merrily We Roll Along — we’ll have to wait for the next installment for an overview of more greatness that followed, such as 1984’s Sunday in the Park with George — one sees the lyrics for A Little Night Music charm off the page; and yet, interestingly, those for West Side Story seem lonely without Bernstein’s soaring score.

A recurring “”grudge” is Sondheim’s disdain for critics: “The sad truth is that musicals are the only public art form reviewed mostly by ignoramuses.” Remembering how for years Sondheim’s music was skewered as being somehow beneath his lyrics — nothing could be more mistaken — you might have to largely concur with the composer’s assessment.

Other surprises: Sondheim’s choice of “Someone in a Tree” from Pacific Overtures as his personal favorite among his vast catalog of songs. His bafflement at the popularity of “Send in the Clowns.” And a wonderful Oscar Hammerstein anecdote in the section on Sweeney Todd that may well have been part inspiration for Sondheim’s “Finishing the Hat” lyric.  And on and on in this trove of musical treasure.