little known musicians we should hear

Since you mention Alejandro Escovedo first (he is so amazing, if it weren't for corporate radio, he'd be a star and "A Man Under the Influence" would be a best selling album), I'll make a few obscure and not so obscure (just in case) additions:

Steve Earle
Lucinda Williams
Joe Ely's "Love and Danger"
The Flatlanders' "More a Legend Than a Band"
Sid Griffin (Western Electric, The Lost Ryders, The Coal Porters)
Gram Parsons
The Golden Palominos' "This Is How It Feels"
Richard Buckner's "Bloomed"
Greg Brown's "Dream Cafe"
Rosanne Cash's "Ten Song Demo"
Wilco's "Being There"
Old 97's
Chris Smither's "Live As I'll Ever Be"
Townes Van Zandt

That's enough for now. Some of these are OOP and you'll have to search ebay and the used bins. Unfortunately, again because of corporate radio, the good die young.
And THANKS for the recommendations from all -- I'll check them out, too!

Curve - THE best band too few have heard of. Their first albums are choice.

Polyphonic Spree - a new band I recently saw whose name is the descrpition of thier music (they have a chior). They do what few can, marrying happiness and talent.

T Bone Burnett has been around for some time but I only recently discovered his CD of the same name. Not sure what to call it-folk, country, or blue grass but it doesn't stray far from the top of the stack.

Paul Weller's solo albums (since 1990).
I like a lot of Jam songs and some Style council, but his solo albums are really far and away his best material. Poignant lyrics, great melodies, and good musicianship.
He's well known (revered) in the UK, but doesn't seem to have crossed the Atlantic.

Meat Beat Manifesto-dark and electric.
The Gentle People-romance in a spacey 60's.
Scott Walker-Sinatra gone insane.
Elysian Fields-Sexy,bluesy with a touch of angst.
Spirit-These guys were so good, you'd have thought they were
English.Great 60's rock
Gong, Van der Graaf Generator and King Crimson(pre-90's)-
shake hands with progressive rock.
Billbored? Never heard of it.