In this second of WASO’s Discovery Concerts, The Art of Orchestration, the dessert arrived before the main course. But not before the entrée. And what an entrée it was.

Organist Joseph Nolan’s playing is marked by a strange mixture of perfectionism and impetuosity. Whence comes its dizzying verve, its febrile intensity. So as far as curtain-raisers go, this performance of Bach’s Toccata and Fugue in D minor on the Perth Concert Hall organ was always going to be an exciting proposition.

And exciting it was, fleet fingers and feet finding – I don’t know how – time to change stops as they sped from cadence to thunderous cadence through sometimes crisply tessellated, sometimes thickly polyphonic labyrinths. The applause was equally thunderous.

A hard act to follow, you might think. But Asher Fisch knew what he was about. Plenty of time for the tension to dissipate, the pulses to slow, as he took us through conductor Leopold Stokowski’s approach to orchestrating Bach’s piece, with Nolan still on hand so passages in the original could be compared with passages in the arrangement.

Asher Fisch. Photograph courtesy of WASO

Although Fisch acknowledged the Stokowski could be seen as in “bad taste” today – indeed, he even went so far as to apologise for performing it at all – he pointed out the skill and care with which Stokowski had assigned certain passages to specific sections of the orchestra – upper strings, lower strings, woodwinds, brass etc. – the better to clarify, rather than obscure, the import of the original.

This was as tantalising as the chef explaining how he prepared the dessert before you were allowed to eat it. Which we finally did, with relish. This is a terrifically fun piece. You might even call it camp. Either way, Fisch and WASO, tucking in with equal gusto, managed to set our pulses racing again. No apologies necessary: all was forgiven.

Then what should have been the second course: five lieder, from a composer one could never accuse of writing in bad taste, at least not today: Richard Strauss. Here, WASO Artist in Association, soprano Siobhan Stagg, joined WASO and Fisch for exquisite performances of Morgen!, Ich wollt’ ein Sträusslein binden, An die Nacht, Freundliche Vision and Cäcilie.

The first and last we had, in their entirety, both in their piano (with Fisch as pianist) and voice originals and Strauss’ own orchestrated versions. Fisch offered penetrating insights into all of them, and despite the love and, yes, tenderness, he, Stagg and WASO lavished on these miniature masterpieces, there was time for all of us to reflect, in our own way, on the nature of the journey from keyboard to orchestra.

An organ, with its tonal, dynamic and timbral range, is an orchestra in itself, so perhaps the journey is shorter. With the piano… well, listening to Strauss’s piano originals we have beautifully shaded monochrome drawings. Then, with his orchestral versions we have oil paintings. But not thick with impasto: more luminous with thin transparent glazes.

It was clear, listening to Fisch’s piano playing, that he was still hearing these orchestral versions in his imagination. Another lesson for us as mere audience members. Or rather an invitation: when listening to solo instrumental works, to create our own orchestrations, in our own heads, as we listen. A colouring-in exercise, though not by numbers: by example.

Following the intermission came the main course, and a masterclass in orchestration: Ravel’s famous 1922 arrangement of Mussorgsky’s suite for solo piano, Pictures at an Exhibition. Here, Fisch went to great pains to point out, by playing excerpts from both scores first on the piano and then conducting the orchestra, that Mussorgsky, contrary to popular belief, must have intended this richly conceived, multi-layered work for orchestration.

He certainly convinced this listener. Either way, the subsequent full performance by the orchestra – wailing woodwinds, sonorous brass, scampering strings and threatening percussion animating animals, children, markets, gardens, catacombs and castles in a welter of vivid imagery – again returned us to this idea of painting pictures in sound.

Because Mussorgsky was quite literally doing that: portraying, in sound, the subjects in the pictures of his late friend, the architect and artist Viktor Hartmann. Ravel having clothed the pictures in orchestral colour, we are free to dream our own worlds.

And thanks to these Discovery Concerts, which with their charm and interest and relaxed atmosphere call to mind the spirit of Leonard Bernstein’s Young People’s Concerts, we’re able to dream those dreams with just a little more clarity and understanding.