Unfortunately, I feel that
Married Sex is not a substitute for
Sheet Music. The books really serve different audiences.
Sheet Music is geared towards newlyweds.
Married Sex is geared more towards a general audience.
We received
Married Sex when we signed up for the Married Sex Conference.
https://www.marriedsexconference.com/ It is a good book, no question. We have been married 40 years and still learned from it. It is excellent in how it deals with the relationship and emotional aspects of married sex. And granted, it is geared for a general audience and does not assume any prior knowledge about sex. It has a footnote explaining what foreplay is

. As pointed out in the book, a lot of married people are woefully ignorant about sex. Debra Felita's research shows that 25% of married couples do not get ANY premarital sex information.
However,
Married Sex is woefully inadequate as an only source of premarital sex information. The words "kegel" and "hymen" do not appear in the book. There is no advice for first intercourse. Oral sex is discussed, but the word "semen" does not appear anywhere in the book. There are no anatomical diagrams. They refer to the "vulva" as the "vagina." They admit that "vulva" is the proper word, but in several instances, because of the ambiguity of the way they use "vagina", it is not clear what they are talking about. "Frenulum" is mentioned, but is described as "the top, spongy part of the penis." That's not where mine is

.
Sheet Music should not be the only source of premarital sex education either of course. When we got married there was no
Sheet Music. We relied on secular sources, and did not lose our morals as a result. But given the reluctance of evangelicals to have any discussion about sex (which I believe has gotten worse over the last 40 years, BTW) secular sources are not something that a lot of Christians would read. Had
Sheet Music been available when we needed it, it would no doubt have been our primary source.
So, I would say ideally to read
Married Sex first, then
Sheet Music.
Married Sex will provide a great introduction. But if you are going to only read one of the two books, definitely go for
Sheet Music.