Greatest Songwriter of all time


I was reading the Dylan post and it got me thinking. There are many great songwriters that come to mind, my expertise/knowledge is primarily with rock music. If you could only pick three, what would they be? My vote for best lyrics goes to:

Jim Morrison
Bruce Springsteen
Elvis Costello

Best music goes to:

Mark Knopfler
Stevie Ray Vaughn
Frank Zappa
jeffloistarca
Listening to the new one titled "Used Songs" by Tom Waits, a compilation of songs from the early years, reminded me what a great songwriter he is, so I'll add him to my list.
I second Van Morrison,also John Lennon,Joni Mitchell,Paul M.,Steve Winwood, and several others.
Philefreak, How dare I over look Van the man Morrison. I agree 100%. Love the MAN VAN.
PINK FLOYD they made some of THE best music IMHO. But i like more of the stuff after syd barrett left the band
Lots of great choices so far, and I agree with some of them; but I guess we're not sticking to Rock. So, for something different I nominate Franz Schubert and Ernesto Lecuona.