"Yacht rock" isn't what Hall and Oates thought they were making in the '70s, and to this day, Daryl Hall hates the term. Christopher Cross wasn't aware that his Best New Artist Grammy win would one day be considered a peak yacht rock moment; Toto didn't know the question, "Does any member of Toto play or sing on it?" would one day be considered a rule-of-thumb question for classifying a song as yacht rock or not; and Rupert Holmes didn't realize that his "Escape (The Piña Colada Song)" would one day be considered "the yacht rock national anthem."

The term is generally believed to have been coined by a radio DJ in the '80s, after yacht rock had already peaked, but it was immortalized by a web series that started in 2003. Yacht Rock told satirical stories of radio staples like the Doobie Brothers' "What a Fool Believes."

That laid the groundwork for a yacht-rock resurgence that's encompassed everything from tribute bands to Christopher Cross singing "Sailing" on The Tonight Show. In The Yacht Rock Book, Greg Prato's new oral history of the genre, Cross remembers that Jimmy Fallon asked him to don a captain's hat. Cross was reluctant to poke fun at his signature hit — until he walked out, and there were all the Roots rocking yachtwear.

So what, exactly, is yacht rock? Prato doesn't precisely define it, but his sources generally agree it's the smooth rock music that enjoyed its commercial peak from the mid-1970s to the mid-1980s. Saxophones and Rhodes electric pianos are the signature instruments of yacht rock, which is influenced by jazz and R&B without being jazz or R&B. It was largely played and enjoyed by white guys, although there was a black crossover audience for artists like Michael McDonald — and a "yacht soul" sub-genre with artists like Earth, Wind and Fire.

The best-known yacht rock artists are Fleetwood Mac, the Eagles, the Doobie Brothers, and Steely Dan — but really, the quintessential yacht-rockers are those artists you would only maybe kind of recognize by name. We're talking Looking Glass, Poco, Firefall, Orleans. A famous frontman like Glenn Frey doesn't really work for yacht rock, because yacht rock isn't about a charismatic singer. It's about a smooth, polished studio sound that goes down easy around 4 p.m. on...well, on the deck of a yacht.

Real yacht rock is a studio musician's game: even if you think you hate yacht rock, you definitely love some songs that yacht-rockers made possible. Michael Jackson's Thriller? The studio crew behind that album could have raised anchor at a minute's notice. The formative yacht-rock influences included Byrds-style country rock and the aspirational pop of the Beach Boys: songs, expertly arranged and performed, that you could drift away to.

On the other end of the spectrum, the definitive anti-yacht-rock artist is...that's right, Jimmy Buffet. "We hate Jimmy Buffet," says "Hollywood Steve" Huey, host of the web series and co-host of the Beyond Yacht Rock podcast. "His lyrics are dumb, the escapist fantasies he paints are just lame [...] and the biggest thing about why we don't consider him yacht rock is his music is very, very simple." Complex music with the occasional, tasteful reference to sailing or drinking...now that's yacht rock. "Sailing away again to Margaritaville" is just sloppy.

Prato's sources are, appropriately for the genre, not household names. We hear from Oates but not Hall, from the Eagles' Don Felder but not Don Henley, and from drummer Liberty DeVitto but not Billy Joel. Huey is by far and away the most informative and entertaining, which is his job. The musicians tend to be, surprise surprise, a little boring. Even the chapter on partying runs to only five pages, with scandalous revelations like, "There were a lot of women involved in the whole thing that was going on" (Felder).

By and large, these men (and yes, they are 100% men except for Toni Tennille) are appealingly modest. These were never crotch-grabbing provocateurs, which is why in a chapter on the decline of yacht rock, they almost all blame MTV. More than one explicitly cites the Buggles as prophetic: video did kill the yacht-rock radio stars, with their bushy beards and tacky shirts.

(Of course, there's an exception to every rule, and the exception to the yacht-rock modesty rule is Air Supply's Graham Russell. On "Making Love Out of Nothing At All": "I think that's a great, great song." On "The One That You Love": "One of the great pop vocals of our generation." On "All Out of Love": "It's one of the greatest ballads of all time, in my opinion — and I'm not just saying that because I wrote it.")

As a volume, The Yacht Rock Book is uneven. It feels like instead of editing, Prato just kind of sorted. Hence, in addition to chapters on songcraft, album art, and fashion (or the lack thereof), there are inexplicable chapters devoted to the political career of Orleans' John Hall; to "Captain" Daryl Dragon's memories of the Beach Boys; and to Captain & Tennille's 2014 divorce.

In the end, the book makes a solid case for yacht rock as more than a joke. It's easy to make fun of because it's so easygoing and, by definition, bland — but yacht rock playlists wouldn't be proliferating if the songs didn't hold up to repeated plays. The genre of chillwave (Neon Indian, Washed Out, Toro Y Moi) brings yacht rock values — pristine musicianship and a softly jazzy vibe — into the 21st century's electronic soundscape.

Other artists pay yacht rock homage more directly. The yacht rock revival may have peaked with Thundercat's 2017 "Show You the Way": an eminently buzzworthy young singer-songwriter recruiting Kenny Loggins and Michael McDonald to lend their legendary pipes to a new song that captures the spirit and, dare I say, the soul of a uniquely smooth era in popular music.