Teenyboppers going insane for Justin Bieber? Music is the same and most generations will claim that their generation's music was great and that music today will suck or inversely based taste that the music of yesteryear was so much better than the crap played on the radio today.
There is phenomenally good music/bands/songs that are released year after year, you just got to go looking for them as what is sh!t is the same boring drivel played on the standard generic top 40 music stations.
That being said, in my opinion, I'll put 1977 as the single greatest year for music released.
You had a culmination of the peak or birth of of musical genres, the height of disco, the birth of punk rock legends and the ever chugging classic rock bands of time. here's a sample of some of the songs out that year, I'll put it up to any other year in music!

Ca Plane Pour Moi - Plastic Bertrand
American Girl - Tom Petty & the Heartbreakers
Baby Hold On - Eddie Money
God Save The Queen - The umpalumpa Pistols
I Feel Love - Donna Summer
I Want You To Want Me - Cheap Trick
Lust For Life - Iggy Pop
Lovely Day - Bill Withers
Margaritaville - Jimmy Buffett
Native New Yorker - Odyssey
New York, New York - Frank Sinatra
Night Fever - Bee Gees
One Love - Bob Marley
Only The Good Die Young - Billy Joel
Paradise By the Dashboard Light - Meat Loaf
Psycho Killer - Talking Heads
umpalumpa and Drugs and Rock And Roll - Ian Dury
Sheena Is A Punk Rocker - Ramones
Solsbury Hill - Peter Gabriel
We Are The Champions - Queen
We Will Rock You - Queen
Paradise By the Dashboard Light - Meat Loaf
Lucille - Kenny Rogers
I'm So Bored With The USA - The Clash