I find that music keeps getting better over time... in certain genres. I listen to a lot of metal, and despite recording and mastering not being ideal for some records, the composition and arrangement in a lot of today's music is amazing, and progressing well beyond what has been realized in the past. Bluegrass-derived acoustic music is also going in many different and exciting directions which have never been travelled before.
|Of course growing up in the 1950s, 1960s and 1970s is more than enough of a musical reason to say that the music of today is not the greatest. Regardless of what genre of music you are listening to from these time periods; there is only one conclusion that can be made and that is that this period was a golden age of music.
And whom do we still cherish from this golden age? The groups and artists who were pushing back the cutting edge, that's who. Hendrix, Joplin, Dylan, Zep, Clapton, etc. etc. etc. Well, guess what? The people who play rock music today are wearing their influences on their sleeves, and are still trying to re-create the cutting edge from 30+ years ago. Well, it's not cutting edge anymore, and it's not surprising that it sometimes sounds tired and overdone.
IMO if you want to hear something truly fresh, don't look to rock music and 5-chord singer-songwriters the way you did in the "golden age". I like a lot of rock music, but I generally don't find the current offerings exciting and inspiring. I listen to DSOTM, and I recognize that it is a mind-blowing piece of work in the context of its time of creation. It was revolutionary, and it still sounds revolutionary. Current rock music is generally not.
Metal and bluegrass are where I look if I'm in search of the unexpected. YMMV of course.
EDIT: I see Sherwood posted essentially the same thing, more eloquently and using fewer words, while I was typing.