This volume of 14 essays, by 14 different authors, on selected works of Stephen Sondheim is aimed principally at an academic audience, and does not cover all of Sondheim's musicals individually. I also use the word "works" rather than musicals, because the essay by Douglas Braverman covers not a musical, but Sondheim's one original movie screenplay, "The Last of Sheila", although Braverman does tie this screenplay back to Sondheim's musicals, not surprisingly.
For the most part, even though the discussions are quite in depth and "academic" in that sense, the essays generally avoid literary jargon, so that Sondheim devotees or fanatics who aren't necessarily literary academics can also potentially derive much enjoyment from this collection. The one essay which lays on the literary terminology rather more is Gary Konas' essay on "Passion". To a lesser extent, Barbara Means Fraser also uses a few "heavier" academic terms of analysis, but since she fairly breezes through each musical in her analysis of the role of the chorus in Sondheim's musicals, there almost isn't time to get bogged down. I must confess as a small matter of personal taste that I found Judith Schlesinger's use of the line from "Sweeney Todd" of 'Don't I know you, mister?' as her essay closer very arch and self-conscious, in an otherwise good essay.
Although this volume certainly isn't "casual" reading, it is accessible enough for the intelligent lay-reader who is willing to focus on the task at hand. Sondheim fans will need no recommendation from me.