Best 70s bands/songs?

I need to catch up on 70s music.. I've listened to all round and I love it so what are the best songs/bands? I love disco, rock, blues, soul, jazz, funk, rhythm n blues etc. What bands/singers are the best? I know about Led Zep, Jimi, Marvin Gaye, Queen etc. But I want to add to my 70s collection because I love 70s music. So who are your fave's from the 70s? Thanks :D