but I offer up Starless and Bible Black by Stan Tracey and Bobby Wellins...

Sweet and Easy by The Van McCoy Strings from 1965

so apols to those unspotified http://open.spotify.com/track/60pIqcF5Smvd3OlXJ2sWQm

It's a wonderful Dexy's instrumental.

Well, you did ask! Here's the first five mins of the side-long 'Hamburger Concerto' from 1974 - otherwise known (and mischievously uncredited by the band) as Johannes Brahms' 'St Antony Chorale' after a theme by Haydn. It was a good theme...

Link Wray : Rumble

'You Know, You Know' - the most powerful and poignant and mysterious 9 notes in (Jazz-)rock, laden with portent and resolve. And also, I'm afraid, in this live version for German TV, a drum solo. Original studio version was a couple of mins...

I like Barry Adamson's cover version of "Diamonds", originally by Jet Harris and Tony Meehan. Best played loud:

http://www.divshare.com/download/7013303-387

Another from Barry Adamson, this time a cover of Elmer Bernstein's theme from "The Man With The Golden Arm".

And one from the RAH (Richard Anthony Hewson) Band - "The Crunch"

Their second best tune after "Clouds Across The Moon"...

by Nightmares On Wax. B-Boy culture, Acid House and a healthy dose of surrealism collide in Yorkshire, sound of British music is changed forever.

I love the Tornados...

Perhaps we shouldn't get too deeply into theme tunes on this thread, but this is just too good an instrumental to miss out.
It's the very definition of "parping" brass - the main title from the film "The Carpetbaggers", written by Elmer Bernstein, performed by Jimmy Smith and used for the BBC's "The Money Programme":

http://www.divshare.com/download/7013909-fd8

A firm handshake and a look of approval to the first person to spot what it is an instrumental edit of. It's not that tricky.

This is or has been played as a warm up track by quite a few club DJs, and I have seen some priceless looks come over people's faces as they realise what they are grooving to.

...The 'World In Action' ITV theme tune, created c.1970: as doom laden yet intoxicating as it gets. There's longer version on youtube (audio only) linking the start and end music (all a jam, apparently, by Shawn Phillips on guitar and Mick Weaver on organ). Shawn claims that he was diddled out of huge royalties (£189,000 he believes) by a guy who took the writing credit to help Shawn get around his non-MU status at the time. Who knew it'd run for decades?

Also sounds like a theme to great lost 60's TV series

Bit of a 'marmite' band but I think that this is a great piece of music whether you like their more wilfully eccentric stuff or not.

as there are no words in the vocal and frankly this is PLAY LOUDER. The Dark Lord Moody DJ Himsen. It's a rocksteady Sunday.

(No ranting about "di black petty booshwah" over this tune):

http://www.divshare.com/download/7018104-ea1

...cut to movie I made about going up Dublin's tallest building...

I'm going out on a limb here. It was a huge seller, but underrated in that it was thought to be a cheap and tacky cash-in, rather than a perfectly crafted thing of disco beauty.
If you want to skip the fairly unnecessary intro, go to 1m23s. To appreciate the seamless morphing into the wonderful Cantina Band section, go to 3 minutes in...

A man so tight that he'd skimp on sidemen to save cash. True fact there for all you anti-jazzers.

DJ Lebowitz playing the Dead Kennedys' "Holiday In Cambodia" on a pub piano:

Track would later feature on WARP's Artificial Intelligence compilation, this original 12" goes for stupid money now...

able to supply "Summer On Signal Hill" by Killer Joe for the benefit of our instrumental lovers everywhere?
Assuming someone might be able to, I won't reveal the composer or personnel involved - perhaps folks who genuinely don't know can register their guesses.
It was occasionally played on Bob Harris's Saturday night show back in the days when I was single and used to invest in all kinds of elaborate timing devices and C120's to tappe it.

I couldn't find this on You Tube so I linked a Spotify link but how about the track Asleep In The Desert from Tejas.

http://open.spotify.com/user/willdabeast/playlist/6uuwVUm8ICQNJr8FQOFBxG

"The Pride and the Pain" - B-side to Roxy Music's "Pyjamarama".

Epic/Biblical/B-Movie soundtrack pastiche, crackle-free (first), or in authentically well-played hissy, crackly B-side glory... (second).

"Make way, make way you dogs - the emperor's son will pass this way!".

http://video.google.co.uk/videosearch?hl=en&q=Roxy+music+pride+and+the+p...

Both of these pieces were played in the Arena programme on 'Cool' repeated last week on BBC 4

No matter how well known, it´s still underrated.