Let's say one was to look at the years 1972 and 1979 in terms of fashion (clothes, hairstyles, etc) would there have been a big change? For example, by 1979 were Bell Bottoms still popular? What about long sideburns for men? From those who can remember, were men still wearing long sideburns by the late 70s? Were there any new fashion styles or trends that popped up between 1972 and 1979?

Disco and polyester pant suits!

;D

Though there were changes, I always felt that the 70s was one of those decades (not too unlike the 00s) in which fashion and culture didn't change a hell of a lot when differentiating between the early and later years.

Though by the mid-70s, the whole hippie thing was over with.

I'll give a female perspective -- I went through my teens during the 70's so I was very fashion conscious.

The early 70's meant a lot of post hippie looks, just exiting the 60's, the big influence.  It was all about the psychedlic.  For girls, skirts were almost all the short slender variety.  Tie dye was groovy.  Denim was getting increasingly popular - that would continue (patchwork denim showed up alll over the place).  Hip huggers were cool then.  Polyester wasn't the big "IT" yet.

By the mid 70's, the peasant (organic) look had emerged.  Skirts suddenly got longer (ala the tiered peasant skirt).  By contrast, with disco now in full swing, polyester had become majorly in.  This was the peak time for platform shoes.  Guys just had to have a leisure suit.  (Oddly enough, earth shoes showed up at this time too, along with other sensible alternatives like clogs.)  This was when designer jeans just started to emerge.

The late 70's trended in a few other directions.  I recall the "preppy" look became popular (tartan skirts, polo shirts, ribbed sweater vests, chinos and cords, penny loafers).  Also athletic duds went a little more mainstream (running shorts, sweats, fancy brand athletic shoes, etc.)  We were ditching our platforms for wedge shoes, cowboy boots, and thin(ner) heels.  Designer jeans continued to take off.  For materials, there was a slow return to some of the less polyester-ish choices: leather, wool, lace, plus faddish looks like glitter.  I remember velour was newly introduced and much beloved.  It was almost the 80's...

  Levi Big Bells, Frye boots, and a shirt, usually with some kind of design on the shoulders. These served me well from early to late seventies.