The 1970s were memorable for oh-so-many reasons.

Or so I'm told. I wasn't around back then. (Sorry ... had to throw that in there.)

The decade was especially important for the radio biz. It's when many of the formats we know and love — Top 40, country, rock — evolved into their present forms.

Austinite Kim Simpson chronicles those changes in his book, "Early '70s Radio: The American Format Revolution."

"I've always been fascinated by early '70s radio," he said. "The industry was trying to make sense of a new sound. It was such a hodgepodge."

Simpson, citing figures from Broadcast magazine, reports the number of radio formats was in the single digits at the start of the '70s. At the end of the decade, that number had exploded, with 133 different formats available — each targeted at a very specific audience.

The one-size-fits-all days of radio had come to an end. With the help of "radio doctors," broadcasters began to narrowcast. Stations became laser-focused on teens, housewives and even rural America.

"There was all this hand-wringing about what was going to happen," he said.

Some even speculated some genres, such as country, could fade into the sunset. Clearly that didn't happen. In Austin, for instance, two country stations are routinely among the city's top-rated stations.

Conducting research for the book wasn't easy. Many of the trade publications Simpson had scoured as a child were nowhere to be found. He eventually hit pay dirt at the Library of Congress.

"Unfortunately, a lot of that stuff got thrown away," he said.

So, with XM, Pandora and iHeartRadio growing in popularity, will we see another radio revolution in the near future? Simpson, who has worked with Austin stations KOOP-FM and KUT-FM, thinks it's likely.

"I don't think terrestrial radio is going anywhere, but who knows what kind of experimentation we might see," he said. "There are some people who think radio is terrible right now, but there is all kinds of hope for the future. It doesn't have to be bad."

Yes, KISS-FM still No. 1

The latest numbers are in, and 96.7 KISS-FM continues to stomp the competition in Austin's ratings race.

In fact, the home of Flo Rida, Lady Gaga and Maroon 5 has — yet again — widened its lead.

Further down the list, all Christmas, all the time paid off for Majic 95.5, helping it jump seven spots, going from 10th place in November to third place in December.

The news wasn't as good for KASE 101, which tumbled from third place to sixth place — its worst showing in months.

Also worth noting: Newly launched Comedy 102.7 has wasted little time grabbing a sizable audience. In 15th place, it topped several established frequencies.

Average quarter-hour ratings as of Dec. 7, courtesy of Radio-Info.com (numbers in parentheses indicate rank as of Nov. 9):

• 1.) 96.7 KHFI-FM (1)
• 2.) 590 KLBJ-AM (2)
• 3.) 95.5 KKMJ-FM (10)
• 4.) 102.3 KPEZ-FM (6)
• 5.) 103.5 KBPA-FM (4)
• 6.) 100.7 KASE-FM (3)
• 7.) 107.1 KLZT-FM (5)
• 8.) 90.5 KUT-FM (8)
• 9.) 104.3 KLQB-FM (7)
• 10.) 98.1 KVET-FM (9)

You 'Love' Rihanna

She's still got it. Barely.

Rihanna continues to have the most-played song on Austin's airwaves, according to AllAccess.com. The margin of victory, however, is eensy.

Her 'We Found Love' was played on local stations 181 times Dec. 27 through Jan. 2, followed closely by LMFAO's 'Sexy and I Know It,' which had 175 spins.

Moving up the charts: Zac Brown Band's 'Keep Me in Mind,' Andy Grammer's 'Keep Your Head Up'" and Roscoe Dash's 'Good Good Night.'

Here are the top five songs played on a random sampling of local stations:

Mix 94.7

• Hot Chelle Rae, `Tonight Tonight' - 51 spins
• Maroon 5, `Moves Like Jagger' - 51
• Gym Class Heroes, `Stereo Hearts' - 50
• Gavin DeGraw, `Not Over You' - 28
• Kelly Clarkson, `Mr. Know it All' - 27

Beat 102.3

• Jay Z and Kanye West, `(Expletive) in Paris' - 122
• Lil Wayne, `She Will' - 120
• J. Cole, `Workout' - 116
• Drake, `Headlines' - 115
• Flo Rida, `Good Feeling' - 70

93.3 KGSR

• Foster the People, `Don't Stop' (`Color On The Walls') - 44
• Snow Patrol, `Called Out in the Dark' - 43
• Ryan Adams, `Lucky Now' - 42
• Black Keys, `Lonely Boy' - 40
• Coldplay, `Paradise' - 40

Majic 95.5

• The Band Perry, `If I Die Young' - 30
• Andy Grammer, `Keep Your Head Up' - 28
• Lady Antebellum, `Just a Kiss' - 28
• Bruno Mars, `Just the Way You Are' - 28
• Adele, `Someone Like You' - 27

Around the dial ...

"Walton and Johnson" has joined the Talk Radio 1370 AM/96.3 FM lineup, airing from 5:30 to 10 a.m. weekdays. "The Radio Gawds," as they're known, are based in Houston, where their oh-so-manly show is heard on KKRW-FM. ... Read my blog at austin360.com/tvblog or follow @gdinges on Twitter to get the latest updates on local radio and TV stations.

gdinges@statesman.com; 912-5987