Here is my tentative CHALLENGE submission with all the requested instruments plus a double bass. To view/typeset the sheet music and listen to the music, there are basically two ways:

a) use a programme called abc2xml to transform the ABC to MusicXML, which then can be read into Sibelius, Finale, MuseScore and many other notation programmes.

b) enter the ABC text into ABC software such as EasyABC or ABCExplorer.

Everybody is welcome to improve upon my proposals, or make their own. Add other instruments such as "The b-b-b-b-b-b-bodh-rán". I suggest that submitters only post the part starting "V:", to work with the same "header" (i.e. the lines from "X:" to "K:C").

X:1
T:Orchestra Song Additions
L:1/8
I:linebreak $
K:C
%
V:picc name="Piccolo" clef=treble^8
%%MIDI program 72
g2 | g>e e "(whisle)" g e'c'| b/c'/d'/b/ g2 g2 | g>f f "(whisle)" g f'd'| c'/d'/e'/c'/ g2 g2 |
w:The pic-co-lo ******** can prickle, oh! ********* and
g>e e "(whisle)" g c'e'| !trill!g'4 g2 | g>f f "(whisle)" g f'd'| c'4 |]
w:tickle, oh! ***** like sick, oh lo!
%
V:harp name="Harp" clef=treble
%%MIDI program 46
G,2|(3G,CE (3GEG c2 | (3G,B,D (3GDG B2 |
w:Not eas-y to tune is the harp, oft-en it's flat or it's sharp,
(3G,B,D (3FGB d2| (3CEG (3cGc e2 |
w:but if the tu-ning is right, we will have pur-est de-light.
(3G,CE (3GEG c2 | (3G,B,D (3GDG B2 |
w:Pluck-ing like plin-ke-ti-plong, oft-en it's right or it's wrong;
(3G,B,D (3FGB dG,| (G,2 !slide!c2) |]
w:if you're a-fraid that you'll miss, just gllll-iss!
%
V:trb name="Trombone" clef=bass
%%MIDI program 57
G,G, |G,4 E,C,| D,6 | G,4 D,2 | E,4 G,G,|
w:The trom-bone does its own, drawn and blown. And its
G,4 E,C,| D,2 D,4 | G,4 D,2 | E,4|]
w:tube is cy-lin-dric, not a cone!
%
V:cello name="Cello" clef=treble_8
%%MIDI program 42
G,2 |G, E,3 G,C| B, F,3 G, A, | B,C DC B,A, | G, E,2 G, E,F,|
w:The cel-lo can sound mel-low, if the play-er knows to treat it well, oh, but if some
G, E3 EF | G F3 DC| B,C D2 F2 | E C3|]
w:fel-low makes it bel-low, it turns lem-on juice to jell-o.
%
V:db name="Double bass" clef=bass
%%MIDI program 43
G,2|C,3 C, B,,A,,| G,,4 G,,2| G,,3 A,, G,,F,,| E,,4
w:Deep down, the dou-ble bass will pace, but hard-ly race,
G,,2|E,,2 E,,2 E,,2| G,,4 G,,2| G,,2 B,,2 G,,2 | C,4|]
w:the foot-ing to brace with firm-ness and grace.