moltopiano, I am also an adult student learning the piano. I have played through
Partridge Pie from which
Four Calling Birds is taken. Similarly, his
A Week of Birthdays.
I have 'had a bash' at
Excursions too and some of
Noctuary, but unless you want to cry and simultaneously empty your pockets of change, I'd leave those two for a while, if I were you!
I recently accompanied
The Bird's Lament from RRB's collection of five songs,
The Aviary - lovely writing for the piano part too.
Etymologically-speaking I believe that 'calling-birds' are in fact 'blackbirds'. I'm no ornithologist, so I don't know how close RRB gets to the call of the blackbird - I'd be inclined to refer to Messiaen for authenticity in that regard.
However, in the piece in question there appear to me, to be three distinct episodes and perhaps one other for which my evidence is rather tenuous:
Bars 1-8, under the 8ve indication, bars 9-13, with the little three-note anacrusis and then the 'cuckoo' call of bars 14-16. These are then repeated, although the LH differs, essentially raised by a tone.
When I started this reply, I was looking at the LH of bars 37-43 for a potential '4th' bird, but now I think that the RH of the
a tempo section probably represents the fourth bird, but
slowed down! Yes, this seems a far better bet! (Bars 32-43).
The character of these four individuals can certainly be made distinct from one another, even in within this short piece. Do get around to playing the complete set of
Partridge Pie; some of it's very witty!