doing the filing clerk thing ... took me ages to work this out :-)...

1. Bob the dog - ISIHAC Theme
2. Chalky - Coronation Street
3. HB - Some Mothers Do 'Ave 'Em
4. Raak - Thunderbirds
5. Kim - The Archers' Theme
6. Rab - Roobard and Custard
7. Bob the dog - Pomp and Curcumstance, Edward Elgar
8. Lib - Blind Date
9. ZK - Dangermouse
10. penelope - Blue Peter
11. Watty - Porridge
12. Kim - Tom & Jerry [Fred Quimby version]
13. Herr Bratsche - Monty Python
14. Raak - Star Trek
15. Bob the dog - Dr Who
16. rab - Have I got News for You
17. Darren - Bergerac
18. Chalky - ??

Does that mean that there is really only one outstanding tune to guess? It seems to me it might be an idea to keep Chalky in the "hotseat" until it's guessed and then have just one at a time, like AVM. Otherwise it will be sheer cacophany.

[B'master] We may have agreed that a maximum of 2 'on the go' is acceptable, in which case it's only fair that rab or Darren can post a new toon being as how they are the latest correct guessers.
A clue to No 18 - I've attempted the main [and most recognisable] theme of my 70s TV show - there *is* an introductory bit if anyone needs more ...

No need - it's The Good Life.

[rab] erm ... no. I'm now thinking I haven't done it very well.

OK then... it didn't quite fit!

OK...
plink plingyplink, plink plingyplink
dada daa-daa-daa-daa daa-daa-daa-daaaa
daa-da-daaaaaaa
dada daaa, da-daa, da-daa, da-daa
da daa-da-daaaaaaa
dadada-daa-da-daa da-daa daa-daa
didididi-dee dee-deeeee-deeeee
dididi dee di-dee di-dee da daa-da-daa
da daaaaaa-daaaaa-daaaaaaaaaaaaaaaaa
hahahahahaha!

That was number 19, of course.

[Chalks}Would it be the Sweeney?

[Darren No 19] the Perusaders perchance?

[Dazed5] Sorry, nope.

Perhaps I should say the "hahahaha!" is part of it.

[Dazed] Yup - certainly is.

[Darren] Rentaghost methinks (Gadzooks mistress Meeker)

Classical, in the loose rather than the strict sense of the word.

Plang-chong. Perlang-chong. Plang-chong. Plang.
Plang plong pli pa-dang!
Bubadidididida bubadidididida (continues underneath)
Daaah-di daaah-di daaaah-do ya-di-da
Daah-di ya-di-daaah do daah do-ya-da
Daaah-di daaah-di daaaah-do ya-di-da
Daah-diiiiiii di-yaaah-di dooo

Can supply more if need be, though I would probably stop well short of the whole thing :)

Ravel's Bolero?

Sorry, forgot the code [Darren No. 19] Rentaghost? [Rab No. 20] Ravel's Bolero?

[Bigsmith] No, although my rendition is not perfect (done from memory).

There might be more plang-chongs in the intro.

[Bigsmith] Correct! Number 19 is, indeed, Rentaghost.

[rab] It's not the opening from Handel's Messiah is it?

Update:
1. Bob the dog - ISIHAC Theme 2. Chalky - Coronation Street 3. HB - Some Mothers Do 'Ave 'Em 4. Raak - Thunderbirds 5. Kim - The Archers' Theme 6. rab - Roobard and Custard 7. Bob the dog - Pomp and Curcumstance, Edward Elgar 8. Lib - Blind Date 9. ZK - Dangermouse 10. penelope - Blue Peter 11. Watty - Porridge 12. Kim - Tom & Jerry [Fred Quimby version] 13. Herr Bratsche - Monty Python 14. Raak - Star Trek 15. Bob the dog - Dr Who 16. rab - Have I Got News For You 17. Darren - Bergerac 18. Chalky - The Sweeney 19. Darren - Rentaghost 20. rab's plang-chonger - ???

[Darren] Nope. A hint?

No 21. Another TV theme. 80's/90's.
Do-dooo,do-do-do-do-do-doooooo
La-laaa, la-la-la-la-la-laaaaa-la [repeat lines 1 and 2]
Da-daaa-da, da-daaaa-da, da-da-da-da-da-daaaaa,
Da-daaa-da, da-daaaa-da, da-da-da-da-da-dahhhhhhhh, bom-bom-bom.

[Dazed5 - number 21] It's Blackadder. [rab - number 20] Yes please.

Number 22. Yet another TV theme from the 80s.

dum-diddliddle-dum-dit-dit dum-diddliddle-dum-dit-...
dododummydummydummydummy-dooooo-do-doooo
do-diddliddliddliddliddliddle-doo-doooo
dododummydummydummydummy-dooooo-do
dodiddliddliddle-dee-dee do-dooo
do-do-do-dooo dee-dee-dee-doooo
dee-dee-dee diddliddliddle-doo
do-do-do-dum-doo do-do-do-dooo-dooo, dee-deeeeee
dum diddliddliddliddliddliddliddliddle.... etc.

[Darren] Sure is.

No. 20; Late romantic, Classic FM friendly piece, though if you're a Classic FM devotee the chances are you've only ever heard the slow movement. I posted the start of the first movement.

Very large orchestra for this one. Composed in the late 1800's... normally

Da-da-da-da-DUM,
...da-da-da-da-DUM,
...da-da-da-da-da-da-da-DUM, da-dum.

I suspect Watty will get this one straight away...

um, sorry about the "normally" there, was going to write something else but deleted it and missed a word.

Um, sorry, this is number 23.

[rab] your number 20 is Rachmaninov's Piano Concerto number 2 in C minor and I claim my £5.

*laughs* Indeed. No. 23, as JLE knows, is my mobile ringtone, also known as Symphony No.2 "Resurrection" by Gustav Mahler.

[JLE] Can't stretch to a fiver, but how about some penny chews? I had a hunch you might get that one :) Did I get the number of opening chords right?

[rab] No, you only had about half of them. There are a full *eight* main chords at the start of each of the first eight bars (which you gave a "plang" to), the first seven each having a "chong" on the lowest bass F of the piano halfway through the bar...

And now a piece that you might be able to guess, just from the rhythm that runs through the entire piece as a background, which I'll give two bars in italics
TUM-tiddly-UM-tiddly-UM-tum
TUM-tiddly-UM-tiddly-UM-tum...
Deeeeeeee, da-da-doo-da-da-da dee, da-da-deeeeeeeeee - Da-da doo-da-da-da-deeee.....