This is the fifth in a series of posts about the history of rock music.

It's 1970. I'm 18 and in my second semester of college. I've just found out the rumor is true: The Beatles have broken up. Now what?

The first thing that happened was that the golden age of rock ended. A sure sign that this was true was that the Beatles' subsequent solo careers were never as compelling as they were when they were part of a group, although George and Ringo were to have moments when they would shine.

The coming of the singer-songwriter movement has been blamed, at least in part, for the passing of the golden age. This theory has been bandied about for decades. For the most part, I buy it. But I need to be a little more specific about what I mean by singer-songwriter.

By the 1970s, most performing artists were writing their own songs rather than interpreting the work of other people. In general, this was a good development. It made the artists' albums more interesting to listen to and more worth owning. It raised the bar for being a rock musician.

But the artists associated with the singer-songwriter movement are another matter.

Musically, Carole King's 1971 hit "It's Too Late" sounds like something she wrote in 1961. The movement ushered in a "mellow" sound that had a tendency to sound cloying and emphasized lyrics that were often trite. As I've already mentioned, I'm catholic in my view of what rock music encompasses. Carole King, Cat Stevens, James Taylor, Harry Chapin, Carly Simon and Jim Croce count as rock musicians. I like them and own some of their albums, but they constituted a quiet, inner-directed, unthreatening branch of rock.

Nevertheless, two of the best rock lyricists of all time, Leonard Cohen and Joni Mitchell, achieved success in the 1970s. I don't particularly care about rock music lyrics. Most of it is doggerel . But Mitchell and Cohen were poets whose words were set to music. With Cohen, in fact, it was never about the music. His voice is flat, his melodies are forgettable and his arrangements are schmaltzy. It's all about the words.

Here's the first verse of one of his best-known songs: "Suzanne takes you down, to her place near the river, you can hear the boats go by, you can stay the night beside her, and you know that she's half-crazy, but that's why you want to be there, and she feeds you tea and oranges, that come all the way from China, and just when you mean to tell her, that you have no love to give her, then she gets you on her wave-length, and she lets the river answer, that you've always been her lover."

The mainstream groups that were popular in the 1970s were kind of boring: Three-Dog Night, The Eagles, Kansas, Foreigner, Journey, Boston, Supertramp and Toto immediately come to mind.

Like everyone else who was listening to music in the summer of 1977, I bought Fleetwood Mac's "Rumours" album. But its main appeal is its lush, slick production and the sincerity of lyrics that reflect the breakup of all of the five members' romantic relationships. That was the extent of its significance.

Before punk, the only subversive music of the 1970s was glam rock, and even that was more a matter of style than substance. David Bowie, T-Rex, Mott the Hoople's "All the Young Dudes," Lou Reed, Iggy Pop, Alice Cooper and Roxy Music were part of this movement, which challenged the dominant hippie culture and traditional gender stereotypes. Many of the artists conveyed an ambiguous sexuality.

There's not much to say about disco, except that I think for many baby boomers the success of that strange side trip marked the end of their willingness to listen to new music. Disco was just too demoralizing. Soon, boomers would become a huge market for the oldies stations that even today give the impression that the 1960s and 1970s happened only yesterday. How weird to live in a time when so many radio stations play only music that was popular 40 to 50 years ago.

The one thing I like about disco is that it was a forerunner of techno music, which I would enjoy 20 years later. But even in the 1970s I was fond of what I would now classify as early electronica: Kraftwerk, Vangelis, Klaus Schulze, Tangerine Dream and Brian Eno.

But the music that really kept me going in the 1970s was so-called progressive rock. It has been widely condemned as overblown and vapid, but I am prepared to spend the next blog post defending it and yammering on about it.