That's asking for a lot, there are so many bands (mostly classical) that inspired and improved the industry. It would be a very different world with out artists like Bob Dylan, The Beatles, Jimi Hendrix, Led Zeppelin, Beethoven, you get the point.
Honestly, I can live with out all of them since it's not really a necessity. However, I want to mention some songs I absolutely adore.
First of, Karn Evil 9 (3rd Impression) by Emerson, Lake & Palmer. A 70s progressive rock group. - http://www.youtube.com/watch?v=zJaEYIQzm30
If you listen to this the whole way through you will notice it just keeps changing, it repeats most parts twice and then straight onto something different. If that's not creative then nothing is, and I can't go with out saying that this is the second most powerful rock song I've ever heard. Also, I love it because they choose a different topic (with help from Sinfield) to sing about other than love or religion, or something similiar. Nope! This about (even though I'm not 100% sure. Probably about 98%) artificial intelligence supporting humans fight a war and then something changes at the end (I'm not spoiling it).
Second, One from Metallica. 80s I think thrash metal group. - http://www.youtube.com/watch?v=EzgGTTtR0kc
A song I discovered when I was very young through Napster (I don't download anymore, I was pressured into it. SHUT UP!), and I'm glad I did because I probably would have only found about them at the age of 20. Possibly the most chaotic song I've ever heard switching from moody dark melody to dramatic to ballistic, so you can't say it's not different. And it's also very powerful through the lyrics and the melody on it's own merits, lyrics being about a war-time novel which is about how they you used to experiment on limbless but still alive soldiers. It's the first non pop rock song I heard and it inspired me to find more interesting songs like it.