Perhaps one of the most popular mind-expanding songs of the late ’60s, here is ‘Crimson and Clover’ by Tommy James and the Shondells. There is an unmistakable feeling that you get from hearing this song, that really just makes you feel so good. And in the last chorus, they use some kind of tremolo modulation that is quite trippy and enjoyable. Accompanied with the song is an equally psychedelic video.